Uwe Wolfram wrote: > > > I did fit an equation of the form 1 = f(x1,x2,x3) using a minimization > scheme. Now I want to compute the coefficient of determination. Normally > I would compute it as > > r_square = 1- sserr/sstot with sserr = sum_i (y_i - f_i) and sstot = > sum_i (y_i - mean(y)) > > sserr is clear to me but how can I compute sstot when there is no such > thing than differing y_i. These are all one. Thus mean(y)=1. Therefore, > sstot is 0. > >
Try http://r-project.markmail.org/search/?q=r+square+nonlinear to find heated debates on this subject. But I fear you supervisor or the reviewer wants it anyway. Dieter -- View this message in context: http://r.789695.n4.nabble.com/Coefficient-of-Determination-for-nonlinear-function-tp3335236p3335719.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.
