# 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.fs2hat" <- function(lam, obj) {
    lD <- obj$matrices$D * lam
    RSS <- obj$pure.ss + sum(((obj$matrices$u * lD)/(1 + lD))^2)
    #\tprint(RSS)
    #\ttrA <- sum(1/(1 + lD)) + obj$offset
    den <- obj$N - (sum(1/(1 + lD)) + obj$offset)
    if (den < 0) {
        return(NA)
    }
    else {
        RSS/(den)
    }
}