As Bert Gunter points out, the statistic R-squared should not be given any grand meaning. However, (also in the archives) I use it in my nonlinear least squares codes as a "sanity check" -- and not more than that. Since it is computed as {1 - (residual SS)/(SS from mean)}, do you really want to use a model if it does little better than a model that is simply the data mean?
I find it useful to run easy-to-compute sanity checks as a way to avoid putting foot in mouth, especially now that computers create output so prodigiously. JN On 04/26/2012 06:00 AM, r-help-requ...@r-project.org wrote: > Message: 54 > Date: Wed, 25 Apr 2012 17:12:52 +0200 > From: Pierre Grison <pgri...@hotmail.fr> > To: <r-h...@stat.math.ethz.ch> > Subject: [R] r-square for non-linear regression > Message-ID: <blu0-smtp2288e7041d27f9e634c3331c4...@phx.gbl> > Content-Type: text/plain > > Hi, > > I saw you discussed about the meaning of the R squared in a nls regression. > Do you have a source or a quotation please? > > kind regards, > > Pierre Grison ______________________________________________ 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.