Summary output for nlmrt object.


Provide a summary output (but involving some serious computations!) of an object of class nlmrt from nlxb or nlfb from package nlmrt.


    ## S3 method for class 'nlmrt'
summary(object, ...)



An object of class 'nlmrt'


Any data needed for the function. We do not know of any!


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: When there are bounded parameters, nls 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. In this case, users may wish to look in the inst/dev-codes directory of this package, where there is a script seboundsnlmrtx.R that computes the nls() standard errors for comparison on a simple problem.

Issue: The printsum() of this object includes the singular values of the Jacobian. These are displayed, one per coefficient row, with the coefficients. However, the Jacobian singular values do NOT have a direct correspondence to the coefficients on whose display row they appear. It simply happens that there are as many Jacobian singular values as coefficients, and this is a convenient place to display them. The same issue applies to the gradient components.


returns an invisible copy of the nlmrt object.


Special notes, if any, will appear here.


John C Nash <>

See Also

Function nls(), packages optim and optimx.

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