pretty <- function(x, n=5) {
	if(!is.numeric(x))
		stop("x must be numeric")
	if(is.na(n[1]) || n[1] < 1)
		stop("invalid n value")
	z <- .C("pretty",l=min(x),u=max(x),n=as.integer(n))
	seq(z$l,z$u,length=z$n+1)
}
