You are indexing with numeric 0's and 1's, which will refer to only the matrix element 1,1 (multiple times), cf:
> matrix(1:9,3)[diag(3)] [1] 1 1 1 > Try one of these: > idx <- diag(3) > 0 > idx <- which(diag(3)>0) > idx <- cbind(seq(len=n), seq(len=n)) (For very large matrices, the third will be more efficient, I believe.) -- Tony Plate roger bos wrote: > Dear useRs, > > Trying to replace the diagonal of a matrix is not working for me. I > want a matrix with .6 on the diag and .4 elsewhere. The following > code looks like it should work--when I lookk at mps and idx they look > how I want them too--but it only replaces the first element, not each > element on the diagonal. > > mps <- matrix(rep(.4, 3*3), nrow=n, byrow=TRUE) > idx <- diag(3) > mps > idx > mps[idx] <- rep(.6,3) > > I also tried something along the lines of diag(mps=.6, ...) but it > didn't know what mps was. > > Thanks, > > Roger > > ______________________________________________ > [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. > ______________________________________________ [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.
