If I use this: rep(1:2,c(5,5)) I'll get 1 1 1 1 1 2 2 2 2 2 Is there a way to do this more efficiently, please? Maybe via do.call? Thanks, Laura mailto: lauraholt_983 at hotmail.com _________________________________________________________________ http://toolbar.msn.click-url.com/go/onm00200415ave/direct/01/