Hi, On Thu, Nov 18, 2010 at 10:25 AM, Martin Tomko <martin.to...@geo.uzh.ch> wrote: > Hi Gerrit, > indeed, that works. Excellent tip! > > For reference, I did this: > > subset1<-subset(summarystats,(Type==1)&(Class==1)&(Category==1)) > > I am still not totally sure when one uses "&" amd when "&&" - I was under > the impression that && stands for logical AND....
If you can't find the appropriate documentation, try to experiment in your workspace: R> c(TRUE, TRUE, FALSE, TRUE) & c(FALSE, TRUE, TRUE, TRUE) [1] FALSE TRUE FALSE TRUE R> c(TRUE, TRUE, FALSE, TRUE) && c(FALSE, TRUE, TRUE, TRUE) [1] FALSE The single logical operators (& , |) run over the entire length of your logical vectors. The doubles (&&, ||) just evaluate the first element of the vectors, and ignore the rest. -- Steve Lianoglou Graduate Student: Computational Systems Biology | Memorial Sloan-Kettering Cancer Center | Weill Medical College of Cornell University Contact Info: http://cbio.mskcc.org/~lianos/contact ______________________________________________ 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.
