an example available on the net goes like > df identifier quantity 1 1 10 2 1 20 3 2 30 4 1 15 5 2 10 6 3 20 > aggregate(df$quantity, by=list(df$identifier), sum) Group.1 x 1 1 45 2 2 40 3 3 20
I'd like Group.1 to retain the name "identifier" and would like to control what "x" get called in the output. Thanks. ______________________________________________ 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.
