d1 <- apply(c0, 1, min) I think does it. John Kane Kingston ON Canada
> -----Original Message----- > From: sergio.fond...@gmail.com > Sent: Fri, 5 Jun 2015 15:06:34 +0200 > To: r-help@r-project.org > Subject: [R] Matrix of indexes to extract sparse data in dataframe > > I would like to avoid a "for loop" to get a vector of data taken from > rows of a data frame for specific columns. > An example is the following (I can't apply min to every row of df, this > is > just an example): > > c0=data.frame(a=c(3,-2,12,7,-23,17) , b=c(-1,-3,14,2,6,19)) > c1=apply(c0,1,which.min) >> c1 > [1] 2 2 1 2 1 1 > > I would like to get a result like the following call, but without > employing a "for loop": > > d1=c(c0[1,c1[1]], c0[2,c1[2]], c0[3,c1[3]], c0[4,c1[4]], c0[5,c1[5]], > c0[6,c1[6]]) >> d1 > [1] -1 -3 12 2 -23 17 > > Thanks a lot for any help! > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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. ____________________________________________________________ Can't remember your password? Do you need a strong and secure password? Use Password manager! It stores your passwords & protects your account. ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.