Revision 03698027c2d84118bd0c53c4a9a5b5d23676f388 authored by HwB on 01 October 2012, 00:00:00 UTC, committed by Gabor Csardi on 01 October 2012, 00:00:00 UTC
1 parent 9fdea5d
Raw File
tri.R
##
##  t r i . R  Triangular matrices
##


tril <- function(M, k = 0) {
    if (k == 0) {
        M[upper.tri(M, diag = FALSE)] <- 0
    } else {
        M[col(M) >= row(M) + k + 1] <- 0
    }
    return(M)
}


triu <- function(M, k = 0) {
    if (k == 0) {
        M[lower.tri(M, diag = FALSE)] <- 0
    } else {
        M[col(M) <= row(M) + k - 1] <- 0
    }
    return(M)
}
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