nlxb or nlfb from package
nlmrt.## S3 method for class 'nlmrt':
summary(object, ...)summary.nlmrt performs a summary method for an object of class 'nlmrt' that
has been created by a routine such as nlfb or nlxb for nonlinear
least squares problems. Issue: nls when there are bounded parameters returns a Standard Error for each of
the parameters. However, this summary does NOT have a Jacobian value (it is set to 0)
for columns where a parameter is masked or at (or very close to) a bound. See the R
code for the determination of whether we are at a bound.
There is a script seboundsnlmrtx.R that computes the nls() standard
errors for comparison on a simple problem.
nls(), packages optim and optimx.