In addition to the suggestion about finding a good initial value, you should also scale your response V2 (and, of course, V0). Divide V2 by 10^4, for example. Now your V0 should also be scaled by this factor. This would likely help with convergence.
Ravi. ------------------------------------------------------- Ravi Varadhan, Ph.D. Assistant Professor, Division of Geriatric Medicine and Gerontology School of Medicine Johns Hopkins University Ph. (410) 502-2619 email: rvarad...@jhmi.edu -----Original Message----- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On Behalf Of sterlesser Sent: Wednesday, May 04, 2011 10:08 AM To: r-help@r-project.org Subject: Re: [R] nls problem with R Thanks Andrew. I am sorry for some typos that I omit some numbers of T2. Based on your suggestion,I think the problem is in the initial values. And I will read more theory about the non-linear regression. -- View this message in context: http://r.789695.n4.nabble.com/nls-problem-with-R-tp3494454p3495672.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. ______________________________________________ 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.
