This does what I was hoping it would: aggregate(tm[,-1],by=list(tm[,10]),FUN="mean")
but I don't know what "tm[,-1]" means (well - the -1 bit anyway. Does it somehow means the whole matrix? Please don't tell me to check the manual - I tried and failed dismally... -- View this message in context: http://n4.nabble.com/tm-1-tp1588804p1588804.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.