Function gradient_quad

lib/matplotlib/tests/test_triangulation.py:478–479

(x, y)

        return a*(x-0.5)**2 + b*(y-0.5)**2 + c*x*y

    def gradient_quad(x, y):
        return (2*a*(x-0.5) + c*y, 2*b*(y-0.5) + c*x)

    x = np.array([0.2, 0.33367, 0.669, 0., 1., 1., 0.])
    y = np.array([0.3, 0.80755, 0.4335, 0., 0., 1., 1.])