curve_test.py 文件源码

def test_curvature(self):
        # linear curves have zero curvature
        crv = Curve()
        self.assertAlmostEqual(crv.curvature(.3), 0.0)
        # test multiple evaluation points
        t = np.linspace(0,1, 10)
        k = crv.curvature(t)
        self.assertTrue(np.allclose(k, 0.0))

        # test circle
        crv = CurveFactory.circle(r=3) + [1,1]
        t = np.linspace(0,2*pi, 10)
        k = crv.curvature(t)
        self.assertTrue(np.allclose(k, 1.0/3.0)) # circles: k = 1/r

        # test 3D (np.cross has different behaviour in 2D/3D)
        crv.set_dimension(3)
        k = crv.curvature(t)
        self.assertTrue(np.allclose(k, 1.0/3.0)) # circles: k = 1/r