On Tue, Dec 2, 2008 at 7:42 PM, philozine <[EMAIL PROTECTED]> wrote: > Dear all: > > This is one of those "should be easy" problems that I'm having great > difficulty solving. I have a vector containing ID codes, and I need to > generate a 3-column matrix that contains all possible combinations of three. > > For example, my ID vector looks like this: > A > B > C > D > E > > I need to generate a matrix that looks like this: > A B C > A B D > A B E > A C B > A C D > A C E > A D B > A D C > A D E
Hi, Does this do what you want? expand.grid(letters[1:5], letters[1:5], letters[1:5]) D > .... and so on. (Yes, this could yield some very large matrices!) It's > totally fine, though less desirable, if the resulting matrix contains > combinations with "duplicates," e.g., A A A, A A B, or whatever. > > Thoughts? I'm pretty much stumped here. Thanks in advance for any help you > can offer. > > Best regards, > > Brandon > > ______________________________________________ > 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. > ______________________________________________ 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.
