/* is series XY and monotonic */
isxymonotonic(s = refwindow(w0), item = 1, member = -1)
{
        local status = FALSE;

        if (not(isarray(s)))
        {
                member = item;
                item   = s;
                s      = refwindow(w0);
        }

        status = isxy(s) ? seriesstatus(s, 12, item, member) : FALSE;

        return(status);
}