Hi Bert, another question for indexing 1. is there a good manual for indexing
2. is it possible to get !%in% f.e x =data.frame("A"=c(1:5),"C"=c("A","B","C","D","E")) y =data.frame("B"=c(1,3,5)) test = x[x$A %in% y$B,] test = x[x$A %in% y$B,] test A C 1 1 A 3 3 C 5 5 E means: the result where I am looking for is: test A C 2 2 B 4 4 D no problem with a loop but in a short way I do not find a solution Kind Regards Knut ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.