def test_swiss_roll(self):
np.random.seed(1234)
X, theta = swiss_roll(6, 120, radius=4.8, return_theta=True)
GT = np.hstack((theta[:, None], X[:, 1:2]))
GT -= GT.min(axis=0)
GT /= GT.max(axis=0)
G = manifold_spanning_graph(X, 2)
self.assertEqual(error_ratio(G, GT), 0.0)
def test_two_moons(self):
np.random.seed(1234)
n1, n2 = 55, 75
theta = np.hstack((np.random.uniform(0, 1, size=n1), np.random.uniform(1, 2, size=n2))) * np.pi
r = 1.3 + 0.12 * np.random.randn(n1 + n2)[:, None]
X = r * np.hstack((np.cos(theta), np.sin(theta))).reshape((-1, 2), order="F")
X[:n1] += np.array([[0, -0.2]])
X[n1:] += np.array([[0.9, 0.25]])
G = manifold_spanning_graph(X, 2, num_ccs=2)
num_ccs, labels = G.connected_components()
self.assertEqual(num_ccs, 2)
assert_array_equal(labels[:n1], np.zeros(n1))
assert_array_equal(labels[n1:], np.ones(n2))
