> * when then looking at str(weblog), > the "-" will stay in the levels, mentioned for the variable weblog$V8 > -> BAD! > > Is this snormal behaviour?
Yes, it is. The idea is that a factor has a given set of levels independent of how often you find them in your data - including the case that a level is not observed at all. E.g. gender cn take levels 'male' or 'female' but you may have a sample of females. > Do I have to throw out the unwanted level by myself? Yes, and it's easy: > x <- factor(c('A','B','C','A','C')) > y <- x[x!='C'] > y [1] A B A Levels: A B C > factor(y) [1] A B A Levels: A B cu Philipp -- Dr. Philipp Pagel Lehrstuhl für Genomorientierte Bioinformatik Technische Universität München Wissenschaftszentrum Weihenstephan 85350 Freising, Germany http://mips.gsf.de/staff/pagel ______________________________________________ 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.