Suppose your matrix is called X. ? sample X[sample(nrow(X)),]
Michael On Wed, Nov 16, 2011 at 11:45 AM, Juan Antonio Balbuena <balbu...@uv.es> wrote: > Hello > This is probably a basic question but I am quite new to R. > > I need to permute elements within rows of a binary matrix, such as > > [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] > [1,] 0 0 0 0 1 0 0 0 0 0 > [2,] 0 0 1 1 0 0 0 1 1 0 > [3,] 0 1 0 0 0 0 1 0 0 0 > [4,] 0 0 0 0 0 0 1 1 0 0 > [5,] 0 0 0 1 0 0 0 0 1 0 > [6,] 0 0 1 1 0 0 0 0 0 1 > [7,] 0 0 0 0 0 0 0 0 0 0 > [8,] 1 1 0 1 0 0 0 1 0 1 > [9,] 1 0 0 1 0 1 0 1 0 0 > [10,] 0 0 0 0 0 0 0 1 0 1 > > > That is, elements within each row are permuted freely and independently from > the other rows. > > I see that is is workable by creating a array for each row, performing > sample and binding the arrays again, but I wonder whether there is a more > efficient way of doing the trick. > > Any help will be much appreciated. > > > > -- > View this message in context: > http://r.789695.n4.nabble.com/permutation-within-rows-of-a-matrix-tp4076989p4076989.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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.