You may want to look at the packages 'leaps'. I don't think it does glm's, but possibly you could modify it to.
Otherwise here is one quick approach (though there are probably better ones): > apply( expand.grid( c(TRUE,FALSE),c(TRUE,FALSE),c(TRUE,FALSE) ), + 1, function(x) as.formula(paste(c('y~1', c('x1','x2','x3')[x]), collapse='+'))) Hope this helps, -- Gregory (Greg) L. Snow Ph.D. Statistical Data Center Intermountain Healthcare [EMAIL PROTECTED] (801) 408-8111 > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Indermaur Lukas > Sent: Tuesday, February 27, 2007 12:46 AM > To: r-help@stat.math.ethz.ch > Subject: [R] fitting of all possible models > > Hi, > Fitting all possible models (GLM) with 10 predictors will > result in loads of (2^10 - 1) models. I want to do that in > order to get the importance of variables (having an > unbalanced variable design) by summing the up the AIC-weights > of models including the same variable, for every variable > separately. It's time consuming and annoying to define all > possible models by hand. > > Is there a command, or easy solution to let R define the set > of all possible models itself? I defined models in the > following way to process them with a batch job: > > # e.g. model 1 > preference<- formula(Y~Lwd + N + Sex + YY) > > # e.g. model 2 > preference_heterogeneity<- formula(Y~Ri + Lwd + N + Sex + YY) etc. > etc. > > > I appreciate any hint > Cheers > Lukas > > > > > > °°° > Lukas Indermaur, PhD student > eawag / Swiss Federal Institute of Aquatic Science and Technology > ECO - Department of Aquatic Ecology > Überlandstrasse 133 > CH-8600 Dübendorf > Switzerland > > Phone: +41 (0) 71 220 38 25 > Fax : +41 (0) 44 823 53 15 > Email: [EMAIL PROTECTED] > www.lukasindermaur.ch > > ______________________________________________ > 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 > and provide commented, minimal, self-contained, reproducible code. > ______________________________________________ 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 and provide commented, minimal, self-contained, reproducible code.