# fields, Tools for spatial data
# Copyright 2004-2011, Institute for Mathematics Applied Geosciences
# University Corporation for Atmospheric Research
# Licensed under the GPL -- www.gpl.org/licenses/gpl.html
"plot.Krig" <- function(x, digits = 4, which = 1:4, 
    ...) {
    out <- x
    #
    #   don't do plots 2:4 if a fixed lambda
    #
    if (x$fixed.model) {
        which <- 1
    }
    fitted.values <- predict(out)
    std.residuals <- (out$residuals * sqrt(out$weights))/out$shat.GCV
    if (any(which == 1)) {
        temp <- summary(out)
        plot(fitted.values, out$y, ylab = "Y", xlab = " predicted values", 
            bty = "n", ...)
        abline(0, 1)
        hold <- par("usr")
        text(hold[1], hold[4], paste(" R**2 = ", format(round(100 * 
            temp$covariance, 2)), "%", sep = ""), cex = 0.8, 
            adj = 0)
    }
    if (any(which == 2)) {
        plot(fitted.values, std.residuals, ylab = "(STD) residuals", 
            xlab = " predicted values", bty = "n", ...)
        yline(0)
        hold <- par("usr")
        text(hold[1], hold[4], paste(" RMSE =", format(signif(sqrt(sum(out$residuals^2)/(temp$num.observation - 
            temp$enp)), digits))), cex = 0.8, adj = 0)
    }
    if (any(which == 3)) {
        if (nrow(out$gcv.grid) > 1) {
            ind <- out$gcv.grid[, 3] < 1e+19
            out$gcv.grid <- out$gcv.grid[ind, ]
            yr <- range(unlist(out$gcv.grid[, 3:5]), na.rm = TRUE)
            plot(out$gcv.grid[, 2], out$gcv.grid[, 3], xlab = "Eff. number of parameters", 
                ylab = " GCV function", bty = "n", ylim = yr, 
                log = "y", ...)
            lines(out$gcv.grid[, 2], out$gcv.grid[, 4], lty = 2)
            lines(out$gcv.grid[, 2], out$gcv.grid[, 5], lty = 1)
            xline(out$eff.df)
            title("GCV-points , solid- GCV model,\ndashed- GCV one", 
                cex = 0.6)
            box()
        }
    }
    if (any(which == 4)) {
        hist(std.residuals)
    }
}