Dear all, I am struggling with the use of regular expression. I got > as.character(test$sample.id) [1] "1.11" "10.11" "11.11" "113.31" "114.2" "114.3" "114.8" and need [1] "11" "11" "11" "31" "2" "3" "8" I.e. remove everything before the "." . TIA, Bernd