swh:1:snp:a4c99a50dc49f82b591f268001b320f8c3ca0041
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Tip revision: dc000f2a5f006d137f66716b086025d618bf8306 authored by John M Chambers on 14 July 2008, 00:00:00 UTC
version 1.0-5
Tip revision: dc000f2
triDiag3.R
triDiag3 <- function(diagonal, upper, lower,
                    nrow = length(diagonal), ncol = nrow) {
    value <- matrix(0, nrow = nrow, ncol = ncol)
    r <-max(nrow, ncol)
    if(r > 1) {
        nu <- min(nrow, ncol-1)
        nl <- min(nrow-1, ncol)
        index <- outer((0:nu)*(nrow+1), 0:2, `+`)
        value[index[1:min(nrow, ncol), 2]] <- diagonal
        if(nu > 0)
            value[index[-1, 1]] <- upper
        if(nl > 0)
            value[index[1:nl, 3]] <- lower
    }
    value
}
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