Thank you very much everybody for your quick reply. My problem was that I could not install packages.
Solution of the problem: It was a Windows 7 problem. I can install the packages if I run R as administrator. Thanks again Katharina [[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.