# fields, Tools for spatial data
# Copyright 2004-2007, Institute for Mathematics Applied Geosciences
# University Corporation for Atmospheric Research
# Licensed under the GPL -- www.gpl.org/licenses/gpl.html
# create a special matrix multiply for diagonal
# matrices. Diagonal matrix assumed to be just a vector.
# see tests directory for tests
# NOTE: this is not a symmetric operation:
#  when a left vector is given it is a diagonal matrix
#  when a right vector is given it is a vector.
#
setGeneric("%d*%", function(x, y, ...) standardGeneric("%d*%"))
setMethod("%d*%", signature(x = "matrix", y = "matrix"), 
    function(x, y) {
        x %*% y
    })
setMethod("%d*%", signature(x = "matrix", y = "numeric"), 
    function(x, y) {
        if (length(y) != ncol(x)) {
            stop("non-conformable arguments in %d*% ")
        }
        matrix(t(y * t(x)), ncol = ncol(x), nrow = nrow(x))
    })
setMethod("%d*%", signature(x = "numeric", y = "matrix"), 
    function(x, y) {
        if (length(x) != nrow(y)) {
            stop("non-conformable arguments in %d*%")
        }
        matrix(x * y, ncol = ncol(y), nrow = nrow(y))
    })
setMethod("%d*%", signature(x = "numeric", y = "numeric"), 
    function(x, y) {
        cbind(x * y)
    })