Running ‘testthat.R’ [758s/335s]
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(),  : 
    number of iterations exceeded maximum of 50
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    number of iterations exceeded maximum of 50
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    number of iterations exceeded maximum of 50
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    number of iterations exceeded maximum of 50
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    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(),  : 
    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(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    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(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    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(),  : 
    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(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    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(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    number of iterations exceeded maximum of 50
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  ── 1. Failure: test normal function of file import of type 1 (@test-clean_dt.R#1
  Value hashes to a97f4cf13a, not ab5287b084
  
  ── 2. Failure: test normal function of file import of type 1 (@test-clean_dt.R#2
  Value hashes to a97f4cf13a, not ab5287b084
  
  ── 3. Failure: test normal function of file import of type 1 (@test-clean_dt.R#2
  Value hashes to eccd89265e, not 1fb62d8498
  
  ── 4. Failure: test normal function of file import of type 2 (@test-clean_dt.R#3
  Value hashes to a0ee41e7db, not f8d57b6e9c
  
  ── 5. Failure: test normal function of file import of type 2 (@test-clean_dt.R#4
  Value hashes to a0ee41e7db, not f8d57b6e9c
  
  ── 6. Failure: test normal function of file import of type 2 (@test-clean_dt.R#4
  Value hashes to 875c4d0842, not 516b7aee57
  
  ── 7. Failure: test normal function of file import of type 2 (@test-clean_dt.R#5
  Value hashes to f66b7686fd, not d32a53505b
  
  ── 8. Failure: test functioning of aggregated function (@test-create_aggregated.
  Value hashes to 4a4ed97b38, not 5a885b7e0a
  
  ── 9. Failure: test functioning of aggregated function (@test-create_aggregated.
  Value hashes to 46d527e146, not d042a19f13
  
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    number of iterations exceeded maximum of 50
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    number of iterations exceeded maximum of 50
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, 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(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    step factor 0.000488281 reduced below 'minFactor' of 0.000976562
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
    singular gradient
  ══ testthat results  ═══════════════════════════════════════════════════════════
  [ OK: 181 | SKIPPED: 2 | WARNINGS: 12 | FAILED: 9 ]
  1. Failure: test normal function of file import of type 1 (@test-clean_dt.R#17) 
  2. Failure: test normal function of file import of type 1 (@test-clean_dt.R#21) 
  3. Failure: test normal function of file import of type 1 (@test-clean_dt.R#25) 
  4. Failure: test normal function of file import of type 2 (@test-clean_dt.R#39) 
  5. Failure: test normal function of file import of type 2 (@test-clean_dt.R#43) 
  6. Failure: test normal function of file import of type 2 (@test-clean_dt.R#47) 
  7. Failure: test normal function of file import of type 2 (@test-clean_dt.R#52) 
  8. Failure: test functioning of aggregated function (@test-create_aggregated.R#25) 
  9. Failure: test functioning of aggregated function (@test-create_aggregated.R#30) 
  
  Error: testthat unit tests failed
  Execution halted