On Fri, Apr 20, 2012 at 03:03:40AM -0700, juliane0212 wrote: > > I'm having some problems computing a matrix being symmetric on both > diagonals. > > Does anyone know a way to get from this matrix > > > M <- matrix(c(1,0,0,0,2,7,0,0,3,4,0,0,6,0,0,0), ncol=4) > > to this one > > M_final <- matrix(c(1,2,3,6,2,7,4,3,3,4,7,2,6,3,2,1), ncol=4)
Hi. Try the following. M[row(M) > col(M)] <- t(M)[row(M) > col(M)] n <- nrow(M) M[row(M) + col(M) > n + 1] <- M[n:1, n:1][row(M) + col(M) > n + 1] all(M == M_final) [1] TRUE Hope this helps. Petr Savicky. ______________________________________________ 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.
