Try this: Matrix(diag(duplicated(matchM)), sparse = TRUE)
On Sun, Aug 8, 2010 at 9:43 PM, david h shanabrook <dhsha...@acad.umass.edu>wrote: > 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. > -- Henrique Dallazuanna Curitiba-Paraná-Brasil 25° 25' 40" S 49° 16' 22" O [[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.
