test_k_means.py 文件源码

def test_k_means_function():
    # test calling the k_means function directly
    # catch output
    old_stdout = sys.stdout
    sys.stdout = StringIO()
    try:
        cluster_centers, labels, inertia = k_means(X, n_clusters=n_clusters,
                                                   verbose=True)
    finally:
        sys.stdout = old_stdout
    centers = cluster_centers
    assert_equal(centers.shape, (n_clusters, n_features))

    labels = labels
    assert_equal(np.unique(labels).shape[0], n_clusters)

    # check that the labels assignment are perfect (up to a permutation)
    assert_equal(v_measure_score(true_labels, labels), 1.0)
    assert_greater(inertia, 0.0)

    # check warning when centers are passed
    assert_warns(RuntimeWarning, k_means, X, n_clusters=n_clusters,
                 init=centers)

    # to many clusters desired
    assert_raises(ValueError, k_means, X, n_clusters=X.shape[0] + 1)