>> (x.n <- cast(x.m, id ~ var, function(.dat){
> + if (length(.dat) == 0) return(0) # test for no data; return
> zero if that is the case
> + mean(.dat)
> + }))Or fill = 0. Hadley -- http://had.co.nz/ ______________________________________________ [email protected] 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.
