When I run your problem in optimx (with all.methods=TRUE), L-BFGS-B fails because the function is evaluated out of range. optimx (actually the optfntools package) from R-forge can trap these, and it is usually a good idea to stop and figure out what is going on. Nevertheless, it seems a solution can be found by other methods, and even by L-BFGS-B if one is prepared to ignore these "glitches".
A big +++ for including an executable example. Of course, I would not have answered otherwise. Note that the optimx and optfntools on R-forge are at the moment undergoing a lot of review and change. Best, JN > Message: 4 > Date: Tue, 8 May 2012 14:35:10 -0500 > From: Wenhao Gui <guiwen...@gmail.com> > To: r-help@r-project.org > Subject: [R] optim question > Message-ID: > <CABZdO=zKr1wsXmTOQ54UieVQfpkAx=cyt0dzip7yt1cjb6e...@mail.gmail.com> > Content-Type: text/plain > > Hello, > > I used optim to find the MLE estimates of some parameters. See the code > below. It works for data1(x). but It did not work for data2 and the error > says" L-BFGS-B needs finite values of 'fn' ". > > data2: c(x, 32) that is, if I added the number 32 at the end of data1. > The error appears "non-finite function value" etc. > > Any comments or suggestions? > > Thanks! > > Wenhao > ______________________________________________ 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.
