I did not think of something like "try". I thouht that there should always be a value if I do a logistic regression but sometimes the values are far from being meaningful. So there is a cut-off. My plan was to change the cut-off. Thanks Johannes
2013/7/15 Bert Gunter <gunter.ber...@gene.com> > I think what you want is > > ?try ##or > ?tryCatch > > ## The second is more flexible but slightly more complicated. > > to trap the error and perhaps refit the model without interaction? > > Cheers, > Bert > > On Mon, Jul 15, 2013 at 10:45 AM, Hermann Norpois <hnorp...@gmail.com> > wrote: > > Hello, > > > > I use glm within a function testing for the appearence of the coexistence > > of (minor allels in a subset of) snps. And then I extract the > > Pr(>|z|)-value for the interaction. Principally it works but sometimes > the > > function stops because this "value for the interaction" is NA. For > > instance, this is the case in the following example: > > > > lz <- glm(trait~rs7572685*rs10520302, data=mus, family=binomial) > >> summary (lz) > > ... > > Coefficients: (1 not defined because of singularities) > > Estimate Std. Error z value Pr(>|z|) > > (Intercept) 0.05614 0.16782 0.335 0.738 > > rs7572685 0.49041 0.41437 1.183 0.237 > > rs10520302 0.49269 0.43514 1.132 0.258 > > rs7572685:rs10520302 NA NA NA NA > > ... > > > > I would prefer some values instead of NA (though it does not make any > sense > > in terms of interpretation) for the sake of the smooth running of my > > function. How is this done? I guess I have to change the offset but I > dont > > understand how. > > Thanks > > > > [[alternative HTML version deleted]] > > > > ______________________________________________ > > 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. > > > > -- > > Bert Gunter > Genentech Nonclinical Biostatistics > > Internal Contact Info: > Phone: 467-7374 > Website: > > http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm > [[alternative HTML version deleted]] ______________________________________________ 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.
