# 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.fgcv.one" <- function(lam, obj) {
    lD <- obj$matrices$D * lam
    RSS <- obj$pure.ss + sum(((obj$matrices$u * lD)/(1 + lD))^2)
    trA <- sum(1/(1 + lD))
    den <- 1 - (obj$cost * (trA - obj$nt - obj$offset) + obj$nt)/obj$N
    # If the denominator is negative then flag this as a bogus case
    # by making the GCV function 'infinity'
    #
    ifelse(den > 0, (RSS/obj$N)/den^2, 1e+20)
}