Running ‘testthat.R’ [11m/13m]
Running the tests in ‘tests/testthat.R’ failed.
Complete output:
  > library(testthat)
  > library(rBiasCorrection)
  > 
  > test_check("rBiasCorrection")
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  ── FAILURE (test-algorithm_minmax_FALSE.R:93:5): algorithm test, type 1, minmax 
  `regression_results` not equal to `regression_results2`.
  Component "plot_list": Component 1: Component 2: Component 1: Component 3: Component 6: Component 1: target is not list-like
  Component "plot_list": Component 1: Component 2: Component 1: Component 7: Component 2: Component 1: target is not list-like
  Component "plot_list": Component 1: Component 2: Component 1: Component 9: Component 2: Component 1: target is not list-like
  Component "plot_list": Component 1: Component 2: Component 1: Component 11: Component 1: target is not list-like
  Component "plot_list": Component 1: Component 2: Component 2: Component 3: Component 5: Component 1: target is not list-like
  Component "plot_list": Component 1: Component 2: Component 2: Component 7: Component 2: Component 1: target is not list-like
  Component "plot_list": Component 1: Component 2: Component 2: Component 9: Component 2: Component 1: target is not list-like
  Component "plot_list": Component 1: Component 2: Component 2: Component 11: Component 1: target is not list-like
  Component "plot_list": Component 1: Component 2: Component 3: Component 3: Component 8: Component 1: target is not list-like
  ...
  
  ── FAILURE (test-algorithm_minmax_FALSE.R:94:5): algorithm test, type 1, minmax 
  regression_results[["plot_list"]] not equal to regression_results2[["plot_list"]].
  Component 1: Component 2: Component 1: Component 3: Component 6: Component 1: target is not list-like
  Component 1: Component 2: Component 1: Component 7: Component 2: Component 1: target is not list-like
  Component 1: Component 2: Component 1: Component 9: Component 2: Component 1: target is not list-like
  Component 1: Component 2: Component 1: Component 11: Component 1: target is not list-like
  Component 1: Component 2: Component 2: Component 3: Component 5: Component 1: target is not list-like
  Component 1: Component 2: Component 2: Component 7: Component 2: Component 1: target is not list-like
  Component 1: Component 2: Component 2: Component 9: Component 2: Component 1: target is not list-like
  Component 1: Component 2: Component 2: Component 11: Component 1: target is not list-like
  Component 1: Component 2: Component 3: Component 3: Component 8: Component 1: target is not list-like
  ...
  
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  ── FAILURE (test-algorithm_minmax_TRUE.R:91:5): algorithm test, type 1, minmax =
  `regression_results` not equal to `regression_results2`.
  Component "plot_list": Component 1: Component 2: Component 1: Component 3: Component 6: Component 1: target is not list-like
  Component "plot_list": Component 1: Component 2: Component 1: Component 7: Component 2: Component 1: target is not list-like
  Component "plot_list": Component 1: Component 2: Component 1: Component 9: Component 2: Component 1: target is not list-like
  Component "plot_list": Component 1: Component 2: Component 1: Component 11: Component 1: target is not list-like
  Component "plot_list": Component 1: Component 2: Component 2: Component 3: Component 5: Component 1: target is not list-like
  Component "plot_list": Component 1: Component 2: Component 2: Component 7: Component 2: Component 1: target is not list-like
  Component "plot_list": Component 1: Component 2: Component 2: Component 9: Component 2: Component 1: target is not list-like
  Component "plot_list": Component 1: Component 2: Component 2: Component 11: Component 1: target is not list-like
  Component "plot_list": Component 1: Component 2: Component 3: Component 3: Component 8: Component 1: target is not list-like
  ...
  
  ── FAILURE (test-algorithm_minmax_TRUE.R:92:5): algorithm test, type 1, minmax =
  regression_results[["plot_list"]] not equal to regression_results2[["plot_list"]].
  Component 1: Component 2: Component 1: Component 3: Component 6: Component 1: target is not list-like
  Component 1: Component 2: Component 1: Component 7: Component 2: Component 1: target is not list-like
  Component 1: Component 2: Component 1: Component 9: Component 2: Component 1: target is not list-like
  Component 1: Component 2: Component 1: Component 11: Component 1: target is not list-like
  Component 1: Component 2: Component 2: Component 3: Component 5: Component 1: target is not list-like
  Component 1: Component 2: Component 2: Component 7: Component 2: Component 1: target is not list-like
  Component 1: Component 2: Component 2: Component 9: Component 2: Component 1: target is not list-like
  Component 1: Component 2: Component 2: Component 11: Component 1: target is not list-like
  Component 1: Component 2: Component 3: Component 3: Component 8: Component 1: target is not list-like
  ...
  
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  ── Skip (test-hyperbolic.R:16:5): test functioning of hyperbolic regression func
  Reason: On CRAN
  
  ── Skip (test-lints.R:14:5): test lints ────────────────────────────────────────
  Reason: On CRAN
  
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  ── Skipped tests  ──────────────────────────────────────────────────────────────
  ● On CRAN (2)
  
  ══ testthat results  ═══════════════════════════════════════════════════════════
  FAILURE (test-algorithm_minmax_FALSE.R:93:5): algorithm test, type 1, minmax = FALSE
  FAILURE (test-algorithm_minmax_FALSE.R:94:5): algorithm test, type 1, minmax = FALSE
  FAILURE (test-algorithm_minmax_TRUE.R:91:5): algorithm test, type 1, minmax = TRUE
  FAILURE (test-algorithm_minmax_TRUE.R:92:5): algorithm test, type 1, minmax = TRUE
  
  [ FAIL 4 | WARN 0 | SKIP 2 | PASS 191 ]
  Error: Test failures
  Execution halted