Thanks very much Petr, that one did just fine! I just wanted to say that it's not that I did no reading at all (in fact I use a book called R for Stata users by Muenchen/Hilbe and another German book called Programming in R when you translate the title) - so yes I am aware that R works quite differently than those other programms and that is what is causing me trouble, I guess. Anyway, I will also check the manual as you recommended, see if it helps.
In any case thanks very much for your help Bernhard -- View this message in context: http://r.789695.n4.nabble.com/Loop-over-several-Variables-add-on-question-tp4648216p4648239.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.