Here goes bert again with etiquette lessons. Why are you so crabby?
On Jun 5, 11:16 am, Bert Gunter <gunter.ber...@gene.com> wrote: > I suggest you consult a local statistician. You could also post to a > statistical help list like stats.stackexchange.com. Your query has > nothing to do with R, but is rather about the meaningfulness (or lack > thereof) of statistical significance in nonlinear modeling. > > -- Bert > > > > > > On Tue, Jun 5, 2012 at 6:49 AM, Nerak <nera...@hotmail.com> wrote: > > Hi all, > > I'm struggling with nls. How do you know if your model is significant? For a > > lm, you get a p-value, but you don't get it for a nls. Is there a way to > > calculate it? > > > For a lm I use this: > > a<-summary(lm(model ~obs)) > > f.stat<-a$fstatistic > > p.value<-1-pf(f.stat["value"],f.stat["numdf"],f.stat["dendf"]) > > > Is there something similar for a nls? > > > The kind of output that I get is: > > > Formula: y ~ exp.f(x, a, b) > > > Parameters: > > Estimate Std. Error t value Pr(>|t|) > > a 1.381e+02 1.192e+01 11.583 3.19e-08 *** > > b 1.790e-02 2.459e-03 7.279 6.19e-06 *** > > --- > > Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 > > > Residual standard error: 13.21 on 13 degrees of freedom > > > Number of iterations to convergence: 6 > > Achieved convergence tolerance: 9.123e-06 > > > I know that my parameters are significant but I need to say something about > > the whole model. > > > Many thanks, > > Nerak > > > -- > > View this message in > > context:http://r.789695.n4.nabble.com/nls-how-do-you-know-if-the-model-is-sig... > > Sent from the R help mailing list archive at Nabble.com. > > > ______________________________________________ > > r-h...@r-project.org mailing list > >https://stat.ethz.ch/mailman/listinfo/r-help > > PLEASE do read the posting guidehttp://www.R-project.org/posting-guide.html > > and provide commented, minimal, self-contained, reproducible code. > > -- > > Bert Gunter > Genentech Nonclinical Biostatistics > > Internal Contact Info: > Phone: 467-7374 > Website:http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pd... > > ______________________________________________ > r-h...@r-project.org mailing listhttps://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guidehttp://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code.- Hide > quoted text - > > - Show quoted text - ______________________________________________ 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.
