Is this what you are looking for in doing computations on the columns of a dataframe?
> x <- > data.frame(group=sample(1:2,10,TRUE),A=sample(1:4,10,TRUE),B=sample(1:5,10,TRUE), + C=sample(1:3,10,TRUE)) > x group A B C 1 1 2 4 1 2 2 4 1 2 3 1 3 2 1 4 2 3 2 2 5 2 4 2 2 6 1 2 5 1 7 2 1 5 2 8 1 1 5 3 9 1 4 3 2 10 2 2 1 1 > # sum in each column > aggregate(x[,-1], list(x$group), sum) Group.1 A B C 1 1 12 19 8 2 2 14 11 9 > # count greater than 2 > aggregate(x[,-1], list(x$group),function(.col) sum(.col>2)) Group.1 A B C 1 1 2 4 1 2 2 3 1 0 > > On Jan 26, 2008 9:13 AM, Anders Bjørgesæter <[EMAIL PROTECTED]> wrote: > Hello > > Is there an analogous function to "rowsum" that count the numbers > according to a given vector (preferably larger than a given value) > instead of summing them? > > E.g. rowsum(x, group) > > X is the dataframe, A B C > 5 0 0 > 1 3 3 > 0 1 12 > and group is the vector; 1,1,2 > > rowsum gives: A B C > 1 6 3 3 > 2 0 1 12 > > > I want: A B C > 1 2 1 1 > 2 0 1 1 > > for e.g. count all > 0. > > Best Regards > Anders > > ______________________________________________ > 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. > -- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem you are trying to solve? ______________________________________________ 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.
