Hi, I'm very new to R and absolutely love it. Does anyone know how to use something in R that functions like a BY command in SAS?
For example, let's say you have a variable x, and you want to see the mean. Easy... > mean(x) But what if you want to see the mean of x conditional on another discrete variable? My best attempts so far are something like... > mean(x, y_cat=1) ...which of course doesn't work. I have downloaded plenty of R user guides that are very informative, but am not seeing much on detailed descriptives or data manipulation (for my life, I can't figure out how to sort an attached data frame, but that's another issue). Thanks. -- View this message in context: http://www.nabble.com/Equivalent-to-a-BY-command-in-SAS-tp16670452p16670452.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.
