[Rd] Residual DF of NLS models (PR#14194)

From: <han_at_enfor.dk>
Date: Tue, 26 Jan 2010 11:05:13 +0100 (CET)


Full_Name: Henrik Aalborg Nielsen
Version: 2.10
OS: Linux (SLES 10 / openSUSE 11.1)
Submission from: (NULL) (77.66.63.89)

There seems to be a bug in df.residual.nls which is triggered when nls is called with argument na.action = na.exclude; in that case 'resid(object)' will contain NA-values which should be disregarded when counting the number of residuals:

df.residual.nls <- function(object, ...) {

    w <- object$weights
    n <- if(!is.null(w)) sum(w != 0) else length(resid(object))     n - length(coef(object))
}

The bug cause the F-test of anova.nls to be wrong.

Replace 'length(resid(object))' with 'sum(!is.na(resid(object)))' ?

... and thank you for producing this fantastic software!

BR
Henrik



R-devel_at_r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel Received on Tue 26 Jan 2010 - 11:56:58 GMT

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.2.0, at Tue 26 Jan 2010 - 12:40:16 GMT.

Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-devel. Please read the posting guide before posting to the list.

list of date sections of archive