def compute_laplacian(I):
if len(I.shape) != 2 or I.dtype != np.float32:
raise RuntimeError
L = np.empty(I.shape, dtype=np.float32)
shakti.compute_laplacian(L, I)
return L
def test_compute_laplacian(self):
f = np.array([[1, 1, 1],
[1, 1, 1],
[1, 1, 1]],
dtype=np.float32)
Lf = np.empty(f.shape, dtype=np.float32)
compute_laplacian(f, Lf)
self.assertAlmostEqual(np.linalg.norm(Lf), 0., delta=1e-8)
def test_compute_laplacian_2(self):
f = np.array([[0, 1, 4, 9],
[1, 2, 5, 10],
[4, 5, 8, 13],
[9, 10, 13, 18]],
dtype=np.float32)
Lf = np.empty(f.shape, dtype=np.float32)
compute_laplacian(f, Lf)
expected_central_Lf = 4 * np.ones((2, 2), dtype=np.float32)
self.assertAlmostEqual(
np.linalg.norm(Lf[1:-1, 1:-1] - expected_central_Lf),
0., delta=1e-8)
