#undef fxyvals
#undef x
#undef y
#undef r
#undef theta

/* define x, y, r, theta for z = F(x, y) */
_defzxys(xl, xu, xi, yl, yu, yi)
{
        local xval, yval, r, theta;

        undefmacro("fxyvals");
        undefmacro("x");
        undefmacro("y");
        undefmacro("r");
        undefmacro("theta");

        (xval, yval, r, theta) = fxyvals(xl, xu, xi, yl, yu, yi);

        /* set globals */
        setvar("x", xval);
        setvar("y", yval);
        setvar("r", r);
        setvar("theta", theta);
}