Nothing to do with glmmPQL (as traceback() would have shown you). I think you are looking for ?try.
On Wed, 3 Sep 2003, Andrej Kveder wrote: > Dear listers, > > First let me appologize if the same mail arrives multiple times. Recently I > had some probelms sending my e-mails to the list. > > I encountered a problem when running glmmPQL procuedure doing multilevel > modeling with a dichotomous outcome. > Those are the two error messages I usually get: > > Error in logLik.reStruct(object, conLin) : > NA/NaN/Inf in foreign function call (arg 3) > > Error in solve.default(pdMatrix(a, fact = TRUE)) : > Lapack routine dgesv: system is exactly singular > > The trick is that the model is a part of a simualtion run, which uses the > same starting variance covariance matrix as a source for a mutlivariate > normal simulated 2 level dataset. So the variations in the data set are just > a part of the stochastic process. In the majority of the cases the model > runs fine, while in some cases I get either of the two error messages. The > model obviously cannot be identified. Does anybody have an idea why? > The second question would relate to the handling of the problem. I don't > even mind that much to have some models unidentified (of cours I would > rather not have them). I would like to detect the possible problem > beforehand in order to instruct the simulation run not to specifiy it. What > is most annoying is that when an error occurs, the program stops the > simulation run and not just skips the model results. Does anybody have an > idea what to do about it? Any suggestions would be most helpfull. I can also > send the R program file if that would help. > > Thanks > > Andrej > > _________ > Andrej Kveder, M.A. > researcher > Institute of Medical Sciences SRS SASA; Novi trg 2, SI-1000 Ljubljana, > Slovenia > phone: +386 1 47 06 440 fax: +386 1 42 61 493 > > [[alternative HTML version deleted]] > > ______________________________________________ > [EMAIL PROTECTED] mailing list > https://www.stat.math.ethz.ch/mailman/listinfo/r-help > > -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help