> Moreno, > > I don't understand exactly what it is you are trying to do. Can you explain what you want your matrices to look like? Perhaps give an example. > > Bryan
Dear Bryan, let's try with an example: i have 8 column vectors v1<-matrix(c(2,5,6,8)) v2<-matrix(c(3,7,9,11)) v3<-matrix(c(13,4,2,7)) v4<-matrix(c(3.4,6,11,21)) v5<-matrix(c (1,9,45,3)) v6<-matrix(c(2,76,4,2)) v7<-matrix(c(34,7,8,1)) v8<-matrix(c (2,6,1,9)) I would like to form a combination of theese vectors in order to obtain a set of matrixes in the form "k-combinations from a set" of n elements, when the set is the number of vectors (in this case 8) and k is the number of columns (in this case 4): in this example, i would like to obtain matrix_1 [,1] [,2] [,3] [,4] [1,] 2 3 13 3.4 [2,] 5 7 4 6.0 [3,] 6 9 2 11.0 [4,] 8 11 7 21.0 matrix_2 [,1] [,2] [,3] [,4] [1,] 2 3 13 1 [2,] 5 7 4 9 [3,] 6 9 2 45 [4,] 8 11 7 3 matrix_3 [,1] [,2] [,3] [,4] [1,] 2 3 13 2 [2,] 5 7 4 76 [3,] 6 9 2 4 [4,] 8 11 7 2 [...] matrix_n!/k!(n-k!) [,1] [,2] [, 3] [,4] [1,] 1 2 34 2 [2,] 9 76 7 6 [3,] 45 4 8 1 [4,] 3 2 1 9 I hope I was more clear! However, thanks in advance, Moreno Tutto Incluso Light: chiami e navighi senza limiti a soli 9,95 euro al mese. Gratis la Sim Tiscali Mobile con 25 euro di traffico! ATTIVA ORA http://abbonati.tiscali.it/telefono-adsl/prodotti/tc/tuttoincluso_light/ ______________________________________________ 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.