Dear R Users, I attempt to estimate a generalized nonlinear least squares model using gnls() from the nlme library.
I wish to restrict some of my parameters using the "L-BFGS-B" method for the "optim" optimizer. However, in contrast to nls() in the same package, gnls() does not accept any `lower' or `upper' argument, nor does the control argument allow for such elements. Unfortunately, the help file does not provide a description of how to include lower or upper bounds, nor did I find any hint in the internet. Example library(nlme) #works but no restriction included fm1 <- gnls(weight ~ SSlogis(Time, Asym, xmid, scal), Soybean, start=c(Asym=17,xmid=50,scal=7),weights = varPower(),control=gnlsControl(opt="optim",optimMethod="L-BFGS-B")) summary(fm1) #does not work fm2 <- gnls(weight ~ SSlogis(Time, Asym, xmid, scal), Soybean,start=c(Asym=17,xmid=50,scal=7), weights = varPower(),control=gnlsControl(opt="optim",optimMethod="L-BFGS-B"),lower=c(0,0,0),upper=c(100,100,100)) summary(fm2) fm3 <- gnls(weight ~ SSlogis(Time, Asym, xmid, scal), Soybean,start=c(Asym=17,xmid=50,scal=7),lower=c(0,0,0),upper=c(100,100,100), weights = varPower(),control=gnlsControl(opt="optim",optimMethod="L-BFGS-B")) summary(fm3) Do you know a way to include lower and upper bounds? And: How do I restrict only selected parameters while I wish others to take any value. Any hints pointing to a solution are highly appreciated. Regards, Philipp Grueber ----- ____________________________________ EBS Universitaet fuer Wirtschaft und Recht FARE Department Wiesbaden/ Germany http://www.ebs.edu/index.php?id=finacc&L=0 -- View this message in context: http://r.789695.n4.nabble.com/gnls-and-L-BFGS-B-in-library-nlme-tp4673341.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.
