Hi, I'm very new to working with sparse matrices and would like to know how I can column permute a sparse matrix. Here is a small example:
> M1 <- > spMatrix(nrow=5,ncol=6,i=sample(5,15,replace=TRUE),j=sample(6,15,replace=TRUE),x=round_any(rnorm(15,2),0.001)) > M1 5 x 6 sparse Matrix of class "dgTMatrix" [1,] 2.983 . 1.656 5.003 . . [2,] . . 2.990 . . . [3,] . 0.592 5.349 1.115 . . [4,] 1.836 . 2.804 . . . [5,] . 6.961 . . . 1.077 I know I can permute entire columns this way > M1[,sample(6,6)] 5 x 6 sparse Matrix of class "dgTMatrix" [1,] 5.003 . . . 1.656 2.983 [2,] . . . . 2.990 . [3,] 1.115 0.592 . . 5.349 . [4,] . . . . 2.804 1.836 [5,] . 6.961 1.077 . . . But I would like the new sparse matrix to look like this...where only the nonzero elements are permuted. [1,] 1.656 . 5.003 2.983 . . [2,] . . 2.990 . . . [3,] . 5.349 1.115 0.592 . . [4,] 2.804 . 1.836 . . . [5,] . 1.077 . . . 6.961 Thanks in advance for any advice! -- View this message in context: http://r.789695.n4.nabble.com/column-permutation-of-sparse-matrix-tp4216726p4216726.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ [email protected] 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.
