plot.newclass <- function(x, y=NULL, 
                          main="", sub="",
                          xlim=NULL, ylim=NULL,
                          axes=TRUE, ann=par("ann"),
                          col=par("col"),
                          ...) {
    xy <- xy.coords(x, y)
    if (is.null(xlim))
        xlim <- range(xy$x[is.finite(xy$x)])
    if (is.null(ylim))
        ylim <- range(xy$y[is.finite(xy$y)])
    opar <- par(no.readonly=TRUE)
    on.exit(par(opar))
    plot.new()
    plot.window(xlim, ylim, ...)
    points(xy$x, xy$y, col=col, ...)
    if (axes) {
        axis(1)
        axis(2)
        box()
    }
    if (ann) 
        title(main=main, sub=sub, 
              xlab=xy$xlab, ylab=xy$ylab, ...)
}