Dear Lotta, Try
my.df <- data.frame(a <- c(1,6,10,11,3,5,10), group <- c(5,5,5,5,9,9,9)) tapply(my.df$a,my.df$group,median) 5 9 8 5 See ?tapply and/or ?aggregate for more information. HTH, Jorge On Fri, Aug 1, 2008 at 1:30 PM, Lotta R <[EMAIL PROTECTED]> wrote: > Hi all, > > I have data that looks like > > number|grouping > > > I would like to preform stats for each grouping > > so > > 1|5 > 6|5 > 10|5 > 11|5 > 3|9 > 5|9 > 10|9 > > Say I would like to take the median for above, I should be returned 2 > lines, > one for group #5 and one for group #9 > > Does this make sense? > > I am sorry for the basic question, can someone give me the name of a good > book as well? > > Thanks, > Lotta > > [[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. > [[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.
