On 22/08/2007, at 8:49 AM, Emmanuel Levy wrote: > Hi, > > I was wondering the what would be the (most efficient) way to generate > a sequence > of sequences, i mean: > > if I have 1,2 and 3. > > I'd like to generate a sequence of length N*3 (N ~ 1,000,000 or more) > > Where random permutations of the sequence 1,2,3 follow each other. > > i.e 1,2,3,1,3,2,3,2,1 > > /!\ The thing is that there should never be twice the same number of > in the same sub-sequence, meaning that this is different from > generating a vector with the numbers 1,2 and 3 randomly distributed.
require(gtools) m <- permutations(3,3) M <- m[sample(1:6,1000000,TRUE),] x <- as.vector(t(M)) ###################################################################### Attention:\ This e-mail message is privileged and confidenti...{{dropped}} ______________________________________________ R-help@stat.math.ethz.ch 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.