Hi, You should use the logical "and", i.e., "&" to tell R that you need condition 1 (first column equals 1) AND condition 2 (second column equals 1) to be true:
which(X[, 1] == 1 & X[, 2] == 1) HTH, Josh On Sun, Nov 14, 2010 at 12:39 AM, gtg <maif...@gmail.com> wrote: > > Hi all, I would like to get the row numbers in X where col1 and col2 are both > 1 > I tried this: > which(X[,c(1,2)]==1) > but it gives me the row numbers where either col1 or col2 = 1 > > What should I do? Thank you. > -- > View this message in context: > http://r.789695.n4.nabble.com/gettng-the-row-number-based-on-column-conditions-tp3041549p3041549.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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. > -- Joshua Wiley Ph.D. Student, Health Psychology University of California, Los Angeles http://www.joshuawiley.com/ ______________________________________________ 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.
