What about aggregate. with(dat, aggregate(HR, list(sub_id=SUBJECT_ID), sd))
shall result in required final output form. Regards Petr [EMAIL PROTECTED] napsal dne 20.11.2008 09:20:36: > pufftissue pufftissue <pufftissue <at> gmail.com> writes: > > > > > What I am getting is indeed: > > > > 7200 23955 34563 8934 > > 16.39977 10.03896 11.234 14.02 > > > > I'd like the final output to be: > > > > subject_id hr_Stand_Deviation > > 7200 16.39977 > > 23955 10.03896 > > 34563 11.234 > > 8934 14.02 > > > > The hard way could go like that; I personally got used to it, but I admit > it is one of the thinks that are unusually difficult in R. > > dat = data.frame(SUBJECT_ID=sample(letters[1:5],100,TRUE),HR=rnorm(100)) > sd.list = with(dat, tapply(HR, SUBJECT_ID, sd)) > data.frame(SUBJECT_ID=rownames(sd.list),sd=sd.list) > > I think Hadley Wickham tried to make life easier with the plyr package, > so I thought something like the below would work out of the box. > However, there must be something wrong with the syntax, the > result is only "approximately" correct. > > Dieter > > library(plyr) > daply(dat,.(SUBJECT_ID),sd) > ddply(dat,.(SUBJECT_ID),sd) > > ______________________________________________ > 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. ______________________________________________ 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.
