Hi Gary, Try
transform(z, y = ifelse(x == 5, y-1, y)) HTH, Jorge On Tue, Feb 22, 2011 at 12:18 PM, Hongwei Dong <> wrote: > Hi, R users, > > I'm wondering if I can identify an element in a column by an element in > another column. For example: > > x<-1:10 > y<-11:20 > z<-cbind(x,y) > z > x y > [1,] 1 11 > [2,] 2 12 > [3,] 3 13 > [4,] 4 14 > [5,] 5 15 > [6,] 6 16 > [7,] 7 17 > [8,] 8 18 > [9,] 9 19 > [10,] 10 20 > > What I want to do is: when x=5, y=y-1 > > Anyone can tell me how to do this? Thanks. > > > Gary > > [[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.
