plot.varcomp <- function(x, xlab = "Levels", ylab = "Variance", type = "b", ...) {
if (!("varcomp" %in% class(x))) stop("Object \"x\" is not of class \"varcomp\"")
plot.varcomp <- function(x, xlab = "Levels", ylab = "Variance", type = "b", ...) {
if (!("varcomp" %in% class(x))) stop("Object \"x\" is not of class \"varcomp\"")