Hi r-help-boun...@r-project.org napsal dne 30.07.2009 10:19:21:
> I am attempting to replicate some of my experience from SAS in R and assume > there are best methods for using a combination of summary(), subset, and > which() to produce a subset of mean values by categorical or ordinal > factors. > > within sas I would write > > proc means mean data=dataset; > class factor1 factor2 > var variable1 variable2; > RUN; > > producing an output with means for each variable by factor groupings as > below: > > *factor1 factor2 obs variable mean* > Level A treatmentA 3 variable1 10 > variable2 22 > > treatmentB 3 variable1 12 > variable2 30 > > Level B treatmentA 3 variable1 10 > variable2 22 > > treatmentB 3 variable1 12 > variable2 30 > > What is the best way to go about this in R? See ?aggregate, ?by, ?tapply and maybe also doBy and plyr packages. Something like aggregate(data, list(variable, factor2, factor1), mean) Best regards Petr > > > > > > > -- > Patrick Schmitz > Graduate Student > Plant Biology > 1206 West Gregory Drive > RM 1500 > > [[alternative HTML version deleted]] > > ______________________________________________ > 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.
