Hi, contrasts(yourvariablename)=contr.treatment(levels(yourvariablename),base=3)
3 is the number of the category that you want to be your baseline. Replace accordingly. Cheers, Daniel ------------------------- cuncta stricte discussurus ------------------------- -----Ursprüngliche Nachricht----- Von: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] Im Auftrag von Stephen Collins Gesendet: Friday, January 23, 2009 12:10 PM An: r-h...@stat.math.ethz.ch Betreff: [R] Categorical Variables and glm() When including categorical variables in a regression, the default in R is to set the first level as the base. Is there an option to specify a different level as the base? Regards, Stephen Collins, MPP | Analyst Health & Benefits | Aon Consulting [[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. ______________________________________________ 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.