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nlmrt (version 2016.3.2)

Functions for Nonlinear Least Squares Solutions

Description

Replacement for nls() tools for working with nonlinear least squares problems. The calling structure is 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.

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Version

Install

install.packages('nlmrt')

Monthly Downloads

251

Version

2016.3.2

License

GPL-2

Maintainer

John C. Nash

Last Published

March 4th, 2016

Functions in nlmrt (2016.3.2)

model2ssfun

Generate a sum of squares objective function from a nonlinear model expression and a vector of named parameters.
wrapnls

Nash variant of Marquardt nonlinear least squares solution via qr linear solver.
nlsmnc

Nash variant of Marquardt nonlinear least squares solution via qr linear solver.
print.nlmrt

Print method for an object of class nlmrt.
modgr

Compute gradient from residuals and Jacobian.
nlfb

Nash variant of Marquardt nonlinear least squares solution via qr linear solver.
nlxb

Nash variant of Marquardt nonlinear least squares solution via qr linear solver.
nlmrt-package

Tools for solving nonlinear least squares problems. UNDER DEVELOPMENT.
modss

Compute gradient from residuals and Jacobian.
model2resfun

Generate a residual function from a nonlinear model expression and a vector of named parameters.
coef.nlmrt

Output model coefficients for nlmrt object.
nlsmnq

Nash variant of Marquardt nonlinear least squares solution via qr linear solver.
nlsmn0

Nash variant of Marquardt nonlinear least squares solution via qr linear solver.
model2grfun

Generate a gradient function from a nonlinear model expression and a vector of named parameters.
model2jacfun

Generate a Jacobian matrix function from a nonlinear model expression and a vector of named parameters.
summary.nlmrt

Summary output for nlmrt object.