As the posting guide requested of you: 0) Do not send HTML mail.
1) Tell us your version of R. Some problems in this area have been corrected recently: if it is not at least 2.3.1, update as asked. 2) Give a reproducible example. On Thu, 13 Jul 2006, Birycki Konrad DomBank Warszawa wrote: > Hello, > > I estimaded two logit models via glm(). A null model (called glm00) and > "full" model with all accessible covariates and interactions between them > (glm1). > > Then I tried to get even better model by step procedure. I tried the > following code: > > > step(glm00, scope=formula(glm1), method="both") > > and another one: > > > step(glm00, scope=formula(glm1), method="forward") > > In both cases step procedure terminated after several steps with a warning: > > > Error in factor.scope(ffac, list(add = fadd, drop = fdrop)) : > > upper scope does not include model > > What does the word "model" refer to? To glm00 (the null model)? To my > knowledge and understanding, the initial null model should have been > included in every step of the search. > > Am I wrong? > > Thanks for all comments :-) > > Konrad Birycki > > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html > -- 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 ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html