On Tue, Jul 20, 2010 at 9:58 AM, <nas...@uottawa.ca> wrote: > For nls, the fixing (or masking) of parameters is not, to my knowledge, > possible. > > This is something I've been trying to get in such routines for over 2 > decades. Masks are > available, but not yet well documented, in Rcgmin and Rvmmin packages. > However, these use > an optim() style approach, which is quite different from nls(). If there's > sufficient > interest and some collaboration, I'd be willing to have a go at providing > such > functionality, but it would take quite a bit of work to provide the full > capability of nls(). >
You can optimize over b while fixing m like this: m <- 1 nls(demand ~ m + b * Time, BOD, start = c(b = 1)) ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
