Thank you very much for the help. I installed data.table package, but I keep getting the following warnings:
> setkey(DT,id,date) Warning messages: 1: In `[.data.table`(deref(x), o) : This R session is < 2.4.0. Please upgrade to 2.4.0+. I'm using R 2.10, but why I keep getting warnings on upgrades. Thanks again. -- View this message in context: http://n4.nabble.com/match-function-or-tp1754505p1755876.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.
