It is a simple problem in that I simply want to convert the For loop to a more efficient method. It simply loops through a large vector checking if the numeric element is not equal to the index of that element. The following example demonstrates a simplified example:
> rows <- 10 > collusionM <- Matrix(0,10,10,sparse=TRUE) > matchM <- matrix(c(1,2,3,4,4,6,7,9,9,10)) > > for (j in 1:rows) if (j != matchM[j]) collusionM[j,matchM[j]] <- > collusionM[j,matchM[j]]+1 > collusionM 10 x 10 sparse Matrix of class "dgCMatrix" [1,] . . . . . . . . . . [2,] . . . . . . . . . . [3,] . . . . . . . . . . [4,] . . . . . . . . . . [5,] . . . 1 . . . . . . [6,] . . . . . . . . . . [7,] . . . . . . . . . . [8,] . . . . . . . . 1 . [9,] . . . . . . . . . . [10,] . . . . . . . . . . Again, this works, I just need the for loop to be more efficient as in my application rows=37000, and I need to do this 100 times. Thanks. [[alternative HTML version deleted]] ______________________________________________ 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.