test_locally_linear.py 文件源码

def test_barycenter_kneighbors_graph():
    X = np.array([[0, 1], [1.01, 1.], [2, 0]])

    A = barycenter_kneighbors_graph(X, 1)
    assert_array_almost_equal(
        A.toarray(),
        [[0.,  1.,  0.],
         [1.,  0.,  0.],
         [0.,  1.,  0.]])

    A = barycenter_kneighbors_graph(X, 2)
    # check that columns sum to one
    assert_array_almost_equal(np.sum(A.toarray(), 1), np.ones(3))
    pred = np.dot(A.toarray(), X)
    assert_less(linalg.norm(pred - X) / X.shape[0], 1)


#----------------------------------------------------------------------
# Test LLE by computing the reconstruction error on some manifolds.