Hi All, When I tried to do logistic regression (with high maximum number of iterations) I got the following warning message
Warning message: fitted probabilities numerically 0 or 1 occurred in: (if (is.empty.model(mt)) glm.fit.null else glm.fit)(x = X, y = Y, As I checked from the Archive R-Help mails, it seems that this happens when the dataset exhibits complete separation. However, p-values tend to 1, and residual deviance tends to 0. My questions then is: -Is the converged model correct? or -Can I limit the number of iterations in order to avoid this warning? If I do so, I�ve checked that the model selected by step can diverge in some cases (I use 10 different presence-absence datasets and 18 explanatory variables), and when I validate the model with independent data, the new model is slightly more powerful (in the most part of cases). Thanks in advance, Guillem Chust ------------------------------------------------------------------ Guillem Chust [EMAIL PROTECTED] Laboratoire Evolution et Diversit� Biologique, UMR 5174 CNRS/UPS UPS Toulouse III, batiment IVR3 118, route de Narbonne - 31062 Toulouse Cedex 4, France Tel 33 (0)5 61 55 67 58 Fax 33 (0)5 61 55 73 27 http://www.edb.ups-tlse.fr/ ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
