⚠️There's a newer version (2016.3.2) of this package.Take me there.
nlmrt (version 2012-12.16)
Functions for nonlinear least squares solutions
Description
nlmrt provides tools for working with nonlinear least
squares problems using a calling structure similar to, but much
simpler than, that of the nls() function. Moreover, where nls()
specifically does NOT deal with small or zero residual
problems, nlmrt is quite happy to solve them. It also attempts
to be more robust in finding solutions, thereby avoiding
'singular gradient' messages that arise in the Gauss-Newton
method within nls(). The Marquardt-Nash approach in nlmrt
generally works more reliably to get a solution, though this
may be one of a set of possibilities, and may also be
statistically unsatisfactory. Added print and summary as of
August 28, 2012.