Hi r-help-boun...@r-project.org napsal dne 30.03.2009 05:17:35:
> In a data frame I have a column "date" and a column "time",now I want > to generate a new column which is the mean of the value of time group > by date. In stata the command is > > egen scalls = mean(time),by(date) > > but I don't know the command in R, can anybody help me? In R you can use ?tapply ?by ?aggregate from base or functions from ?doBy package. Regards Petr > > ______________________________________________ > 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.
