# 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.transform.xY <- function(obj, knots, verbose = FALSE) {
    # find all replcates and  collapse to unique locations and mean response
    # and pooled variances and weights.
    out <- Krig.replicates(obj, verbose = verbose)
    if (verbose) {
        cat("yM from Krig.transform.xY", fill = TRUE)
        print(out$yM)
    }
    #
    # save information about knots.
    if (is.na(knots[1])) {
        out$knots <- out$xM
        out$mle.calc <- TRUE
        out$knot.model <- FALSE
    }
    else {
        out$mle.calc <- FALSE
        out$knot.model <- TRUE
        out$knots <- knots
    }
    #
    # scale x, knot locations and  save transformation info
    #
    out$xM <- transformx(out$xM, obj$scale.type, obj$x.center, 
        obj$x.scale)
    out$transform <- attributes(out$xM)
    out$knots <- scale(out$knots, center = out$transform$x.center, 
        scale = out$transform$x.scale)
    #
    #
    #verbose block
    #
    if (verbose) {
        cat("transform", fill = TRUE)
        print(out$transform)
    }
    if (verbose) {
        cat("knots in transformed scale", fill = TRUE)
        print(knots)
    }
    return(out)
}