> my apologies to everyone taking the time to answer this question. i > didn't explain myself very well. > > i have the indices of the elements of the matrix and the matrix won't > necessarily have zeros everywhere else. is there a way to use the > indices to strip the elements i need? > RTFM ?"[".
> x <- matrix(c(0, 2, 0, 0, 0, 4, 3, 0, 0), nrow=3) > x [,1] [,2] [,3] [1,] 0 0 3 [2,] 2 0 0 [3,] 0 4 0 > ?"[" > xx <- matrix(c(1, 2, 3, 3, 1, 2), ncol=2) > xx [,1] [,2] [1,] 1 3 [2,] 2 1 [3,] 3 2 > x[xx] [1] 3 2 4 > HTH, Ray ______________________________________________ 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