Try this: > y[matrix(c(seq_along(x), x), ncol = 2)] [1] 2 16 12 On Fri, Sep 11, 2009 at 4:17 PM, Luca Braglia <brag...@poleis.eu> wrote: > Hello R-users > > I have a situation like this > > x=c(1,3,2) > > y=data.frame("a"=1:3, "b"=4:6, "c"=7:9)*2 > > So we have > >> t(t(x)) > [,1] > [1,] 1 > [2,] 3 > [3,] 2 > > And > >> y > a b c > 1 2 8 14 > 2 4 10 16 > 3 6 12 18 > > I would like to obtain a vector with number taken from the data.frame: x is > needed as row index > > With c(1,3,2), in this case the ouput should be > > 2 > 16 > 12 > > I've tried a little bit with apply, but unsuccessfully. > > Thank you > > ______________________________________________ > 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.