On Fri, Apr 3, 2009 at 8:43 AM, baptiste auguie <ba...@exeter.ac.uk> wrote: > That makes sense, so I can do something like, > > count <- function(x){ > as.integer(unclass(table(x))) > } > > count(d$user_id) > > ddply(d, .(user_id), transform, count = count(user_id)) > >> user_id website time count >> 1 20 google 930 2 >> 2 20 facebook 1000 2 >> 3 21 yahoo 935 1 >> 4 25 facebook 1015 1 >> 5 61 google 940 1 > > Have I missed a built-in function to obtain this result?
ddply(d, .(user_id), transform, count = nrow) ? Hadley -- http://had.co.nz/ ______________________________________________ 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.