On Tue, 2004-07-13 at 14:07, Jordi Altirriba GutiÃrrez wrote: > Dear R users, > Im a beginner user of R and Ive a problem with permutations that I dont > know how to solve. Ive 12 elements in blocks of 3 elements and I want only > to make permutations inter-blocks (no intra-blocks) (sorry if the > terminology is not accurate), something similar to: > > 1 2 3 | 4 5 6 | 7 8 9 | 10 11 12 ----------1st permutation > > 1 3 2 | 4 5 6 | 7 8 9 | 10 11 12 NO > - - > 3 2 1 | 4 5 6 | 7 8 9 | 10 11 12 NO > - - - > 1 2 4 | 3 5 6 | 7 8 9 | 10 11 12 YES-----2nd permutation > - - > 4 5 6 | 1 2 3 | 7 8 9 | 10 11 12 YES-----3rd permutation > - - - - - - > 4 5 6 | 2 1 3 | 7 8 9 | 10 11 12 NO > - - > ....
You can use the permutations() function in the 'gregmisc' package on CRAN: # Assuming you installed 'gregmisc' and used library(gregmisc) # First create 'groups' consisting of the four blocks groups <- c("1 2 3", "4 5 6", "7 8 9", "10 11 12") # Now create a 4 column matrix containing the permutations # The call to permutations() here indicates the number of blocks in # groups (4), the required length of the output (4) and the vector of # elements to permute perms <- matrix(permutations(4, 4, groups), ncol = 4) > perms [,1] [,2] [,3] [,4] [1,] "1 2 3" "10 11 12" "4 5 6" "7 8 9" [2,] "1 2 3" "10 11 12" "7 8 9" "4 5 6" [3,] "1 2 3" "4 5 6" "10 11 12" "7 8 9" [4,] "1 2 3" "4 5 6" "7 8 9" "10 11 12" [5,] "1 2 3" "7 8 9" "10 11 12" "4 5 6" [6,] "1 2 3" "7 8 9" "4 5 6" "10 11 12" [7,] "10 11 12" "1 2 3" "4 5 6" "7 8 9" [8,] "10 11 12" "1 2 3" "7 8 9" "4 5 6" [9,] "10 11 12" "4 5 6" "1 2 3" "7 8 9" [10,] "10 11 12" "4 5 6" "7 8 9" "1 2 3" [11,] "10 11 12" "7 8 9" "1 2 3" "4 5 6" [12,] "10 11 12" "7 8 9" "4 5 6" "1 2 3" [13,] "4 5 6" "1 2 3" "10 11 12" "7 8 9" [14,] "4 5 6" "1 2 3" "7 8 9" "10 11 12" [15,] "4 5 6" "10 11 12" "1 2 3" "7 8 9" [16,] "4 5 6" "10 11 12" "7 8 9" "1 2 3" [17,] "4 5 6" "7 8 9" "1 2 3" "10 11 12" [18,] "4 5 6" "7 8 9" "10 11 12" "1 2 3" [19,] "7 8 9" "1 2 3" "10 11 12" "4 5 6" [20,] "7 8 9" "1 2 3" "4 5 6" "10 11 12" [21,] "7 8 9" "10 11 12" "1 2 3" "4 5 6" [22,] "7 8 9" "10 11 12" "4 5 6" "1 2 3" [23,] "7 8 9" "4 5 6" "1 2 3" "10 11 12" [24,] "7 8 9" "4 5 6" "10 11 12" "1 2 3" HTH, Marc Schwartz ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html