drBootSpline: no visible global function definition for ‘is’
drBootSpline: no visible global function definition for ‘sd’
drFit: no visible global function definition for ‘is’
drFitSpline: no visible global function definition for ‘is’
drFitSpline: no visible global function definition for ‘smooth.spline’
drFitSpline: no visible global function definition for ‘predict’
gcBootSpline: no visible global function definition for ‘is’
gcFit: no visible global function definition for ‘is’
gcFit: no visible global function definition for ‘plot’
gcFit: no visible global function definition for ‘title’
gcFit: no visible global function definition for ‘legend’
gcFit: no visible global function definition for ‘graphics.off’
gcFitModel: no visible global function definition for ‘is’
gcFitModel: no visible global function definition for ‘as.formula’
gcFitModel: no visible global function definition for ‘nls’
gcFitModel: no visible global function definition for ‘fitted.values’
gcFitSpline: no visible global function definition for ‘is’
gcFitSpline: no visible global function definition for ‘smooth.spline’
gcFitSpline: no visible global function definition for ‘predict’
gcFitSpline: no visible global function definition for ‘lowess’
grofit: no visible global function definition for ‘is’
low.integrate: no visible global function definition for
  ‘smooth.spline’
low.integrate : f: no visible global function definition for ‘predict’
low.integrate: no visible global function definition for ‘integrate’
plot.drBootSpline : empty.plot: no visible global function definition
  for ‘plot’
plot.drBootSpline : empty.plot: no visible global function definition
  for ‘lines’
plot.drBootSpline: no visible global function definition for ‘colors’
plot.drBootSpline: no visible global function definition for ‘dev.new’
plot.drBootSpline: no visible global function definition for ‘plot’
plot.drBootSpline: no visible global function definition for ‘points’
plot.drBootSpline: no visible global function definition for ‘hist’
plot.drFit: no visible global function definition for ‘plot’
plot.drFit: no visible global function definition for ‘title’
plot.drFitSpline: no visible global function definition for ‘colors’
plot.drFitSpline: no visible global function definition for ‘plot’
plot.drFitSpline: no visible global function definition for ‘points’
plot.drFitSpline: no visible global function definition for ‘lines’
plot.gcBootSpline : empty.plot: no visible global function definition
  for ‘plot’
plot.gcBootSpline : empty.plot: no visible global function definition
  for ‘lines’
plot.gcBootSpline: no visible global function definition for ‘colors’
plot.gcBootSpline: no visible global function definition for ‘plot’
plot.gcBootSpline: no visible global function definition for ‘points’
plot.gcBootSpline: no visible global function definition for ‘dev.new’
plot.gcBootSpline: no visible global function definition for ‘par’
plot.gcBootSpline: no visible global function definition for ‘hist’
plot.gcFit: no visible global function definition for ‘colors’
plot.gcFit: no visible global function definition for ‘dev.new’
plot.gcFit: no visible global function definition for ‘plot’
plot.gcFit: no visible global function definition for ‘legend’
plot.gcFit: no visible global function definition for ‘title’
plot.gcFitModel: no visible global function definition for ‘colors’
plot.gcFitModel: no visible global function definition for ‘points’
plot.gcFitModel: no visible global function definition for ‘lines’
plot.gcFitModel: no visible global function definition for ‘plot’
plot.gcFitSpline: no visible global function definition for ‘colors’
plot.gcFitSpline: no visible global function definition for ‘points’
plot.gcFitSpline: no visible global function definition for ‘lines’
plot.gcFitSpline: no visible global function definition for ‘plot’
ran.data: no visible global function definition for ‘runif’
ran.data: no visible global function definition for ‘rnorm’
summary.drBootSpline: no visible global function definition for ‘sd’
summary.gcBootSpline: no visible global function definition for ‘sd’
Undefined global functions or variables:
  as.formula colors dev.new fitted.values graphics.off hist integrate
  is legend lines lowess nls par plot points predict rnorm runif sd
  smooth.spline title
Consider adding
  importFrom("grDevices", "colors", "dev.new", "graphics.off")
  importFrom("graphics", "hist", "legend", "lines", "par", "plot",
             "points", "title")
  importFrom("methods", "is")
  importFrom("stats", "as.formula", "fitted.values", "integrate",
             "lowess", "nls", "predict", "rnorm", "runif", "sd",
             "smooth.spline")
to your NAMESPACE file (and ensure that your DESCRIPTION Imports field
contains 'methods').