err = err + check_value(prs, "Opacity", opac, 0, compare_prec)
err = err + check_value(prs, "LineWidth", lwid, 0, compare_prec)
return err
err = err + check_value(prs, "Opacity", opac, 0, compare_prec)
err = err + check_value(prs, "LineWidth", lwid, 0, compare_prec)
return err