# 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
Krig.make.Wi <- function(out, verbose = FALSE) {
    #
    # If a weight matrix has been passed use it.
    #
    # Note that in either case the weight matrix assumes that
    # replicate observations have been collapses to the means.
    #
    if (out$nondiag.W) {
        temp <- eigen(out$W, symmetric = TRUE)
        Wi <- temp$vectors %*% diag(1/(temp$values)) %*% t(temp$vectors)
        W2i <- temp$vectors %*% diag(1/sqrt(temp$values)) %*% 
            t(temp$vectors)
        return(list(Wi = Wi, W2i = W2i))
    }
    else {
        #
        #  These are created only for use with default method to stay
        # consistent with nondiagonal elements.
        return(list(Wi = 1/out$weightsM, W2i = 1/sqrt(out$weightsM)))
    }
}