test_birch.py 文件源码

def test_n_clusters():
    # Test that n_clusters param works properly
    X, y = make_blobs(n_samples=100, centers=10)
    brc1 = Birch(n_clusters=10)
    brc1.fit(X)
    assert_greater(len(brc1.subcluster_centers_), 10)
    assert_equal(len(np.unique(brc1.labels_)), 10)

    # Test that n_clusters = Agglomerative Clustering gives
    # the same results.
    gc = AgglomerativeClustering(n_clusters=10)
    brc2 = Birch(n_clusters=gc)
    brc2.fit(X)
    assert_array_equal(brc1.subcluster_labels_, brc2.subcluster_labels_)
    assert_array_equal(brc1.labels_, brc2.labels_)

    # Test that the wrong global clustering step raises an Error.
    clf = ElasticNet()
    brc3 = Birch(n_clusters=clf)
    assert_raises(ValueError, brc3.fit, X)

    # Test that a small number of clusters raises a warning.
    brc4 = Birch(threshold=10000.)
    assert_warns(UserWarning, brc4.fit, X)