/* RGB to HTML int color */
rgb2int(r=0, g=0, b=0)
{
        local intcolor = 0;

        if (argc == 1)
        {
                if (isarray(r) && numcols(r) == 3)
                {
                        b = col(r, 3);
                        g = col(r, 2);
                        r = col(r, 1);
                }
                else
                {
                        error(sprintf("%s - 3 column series required for single input", __FUNC__));
                }
        }

        intcolor = ((r & 0xFF) << 16) + ((g & 0xFF) << 8) + (b & 0xFF);

        if (isarray(intcolor))
        {
                setvunits(intcolor, "Composite RGB");
        }

        return(intcolor);
}