>>>>> "KateM" == Katharine Mullen <[EMAIL PROTECTED]> >>>>> on Fri, 7 Sep 2007 20:07:41 +0200 (CEST) writes:
KateM> The thread you linked to regarding Levenberg-Marquardt's supposed lack of KateM> availability is from 2001; it has been possible to get KateM> to the MINPACK implementation of Levenberg-Marquardt within R via the KateM> package minpack.lm KateM> (http://cran.r-project.org/src/contrib/Descriptions/minpack.lm.html) since KateM> 2005. Thanks a lot, Kate. I'm wondering about experiences: Do you know of cases where minpack.lm's nls.lm() solved a (real) problem that nls() would have a problem with ? Beware however -- one of the main things I learned about this field from Doug Bates, co-author of Bates_and_Watts and prinicipal author of S's and R's nls() : It's a *feature* that nls() does not converge sometimes when other methods do falsely claim convergence! Martin Maechler, ETH Zurich KateM> ---- KateM> Katharine Mullen KateM> mail: Department of Physics and Astronomy, Faculty of Sciences KateM> Vrije Universiteit Amsterdam, de Boelelaan 1081 KateM> 1081 HV Amsterdam, The Netherlands KateM> room: T.1.06 KateM> tel: +31 205987870 KateM> fax: +31 205987992 KateM> e-mail: [EMAIL PROTECTED] KateM> homepage: http://www.nat.vu.nl/~kate/ KateM> On Fri, 7 Sep 2007, Jose Luis Aznarte M. wrote: >> Hi! I'm translating some code from Matlab to R and I found a problem. >> I need to translate Matlab's function 'lsqnonlin' >> (http://www-ccs.ucsd.edu/matlab/toolbox/optim/lsqnonlin.html) into R, >> and at the beginning I thought it would be the same as R's 'optim'. But >> then I looked at the definition of 'lsqnonlin' and I don't quite see how >> to make 'optim' to do the same thing. Does anyone have an idea? >> This is apart from the fact that I would like to use the Levenberg >> Marquardt algorithm which is not implemented in R (some discussion about >> this: http://tolstoy.newcastle.edu.au/R/help/00b/2492.html). >> Thank you! All the best, >> >> >> -- -- >> Jose Luis Aznarte M. http://decsai.ugr.es/~jlaznarte >> Department of Computer Science and Artificial Intelligence >> Universidad de Granada Tel. +34 - 958 - 24 04 67 >> GRANADA (Spain) Fax: +34 - 958 - 24 00 79 >> >> ______________________________________________ >> R-help@stat.math.ethz.ch 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. >> KateM> ______________________________________________ KateM> R-help@stat.math.ethz.ch mailing list KateM> https://stat.ethz.ch/mailman/listinfo/r-help KateM> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html KateM> and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@stat.math.ethz.ch 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.