... or combn() in utils. which was the first hit when I googled on "finding combinations in R."
So moral: Use search engines before you post. Cheers, Bert Bert Gunter Genentech Nonclinical Biostatistics (650) 467-7374 "Data is not information. Information is not knowledge. And knowledge is certainly not wisdom." H. Gilbert Welch On Tue, Jan 21, 2014 at 12:57 PM, arun <smartpink...@yahoo.com> wrote: > Hi, > May be this helps: > library(gtools) > > as.data.frame(t(combinations(5,3,1:5))) > # V1 V2 V3 V4 V5 V6 V7 V8 V9 V10 > #1 1 1 1 1 1 1 2 2 2 3 > #2 2 2 2 3 3 4 3 3 4 4 > #3 3 4 5 4 5 5 4 5 5 5 > A.K. > > > > For a column of data, I need to extract all possible unique > combinations of 3 rows and combine the results into a data frame (as > columns). So, for example, if I had a column called "test" that had five rows > (the contents of which were the numbers 1:5) all possible > combinations of 3 rows would be > 1,2,3 > 1,2,4 > 1,2,5 > 1,3,4 > 1,3,5 > 1,4,5 > 2,3,4 > 2,4,5 > 2,4,5 > 3,4,5 > > So for this example, R would extract all the combinations shown, and I would > get a data frame that looked like this > 1 1 1 1 1 1 2 2 2 3 > 2 2 2 3 3 4 3 3 4 4 > 3 4 5 4 5 5 4 5 5 5 > > Note: I am not considering rearrangements of the same three rows > to be unique. In other words, the combinations 123, 132, 213, 231, 312, > 321 are all the same as far as I am concerned. If it is not possible to > do it that way, it will still be helpful, but not quite as helpful. > Thanks for the help! > > ______________________________________________ > 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.
