To all of you who answered me: Thank you so much! Each approach taught me something new and I really appreciate your help!
Best regards, Dana Sevak ______________________________________________ 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.
