Take it in a couple of steps. 'ifelse' will take the evaluation of a logical vector (first parameter) and return it second parameter if TRUE or the third parameter if FALSE:
> X<-c(2,2,1,1,0,0) > X > 0 [1] TRUE TRUE TRUE TRUE FALSE FALSE > ifelse(X > 0, 1,0) [1] 1 1 1 1 0 0 > Now the second and third parameters can also be vectors and the corresponding value will be chosen: > ifelse(X > 0, 1:6, 11:16) [1] 1 2 3 4 15 16 > HTH On Tue, Feb 10, 2009 at 4:44 PM, kayj <kjaj...@yahoo.com> wrote: > > I have a problem with ifelse(), I do not understand how it works. > >> X<-c(2,2,1,1,0,0) >> str(X) > num [1:6] 2 2 1 1 0 0 >> Y<-ifelse(X>0,1,0) >> Y > [1] 1 1 1 1 0 0 >> > > Can some one explain what is going on, I do not understand what ifelse is > doing in this case. Can someone explain the output Y. > > Thanks > > -- > View this message in context: > http://www.nabble.com/ifelse%28%29-tp21943308p21943308.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. > -- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem that 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.
