I can exclude columns by column number using '-'. But I wondering if there is an easy way to exclude some columns by column names.
> x=cbind(c(1,2),c(3,4)) > x [,1] [,2] [1,] 1 3 [2,] 2 4 > colnames(x)=c('a','b') > x a b [1,] 1 3 [2,] 2 4 > x[,-'a'] Error in -"a" : invalid argument to unary operator > x[,-1] [1] 3 4 ______________________________________________ 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.