test_birch.py 文件源码

def test_branching_factor():
    # Test that nodes have at max branching_factor number of subclusters
    X, y = make_blobs()
    branching_factor = 9

    # Purposefully set a low threshold to maximize the subclusters.
    brc = Birch(n_clusters=None, branching_factor=branching_factor,
                threshold=0.01)
    brc.fit(X)
    check_branching_factor(brc.root_, branching_factor)
    brc = Birch(n_clusters=3, branching_factor=branching_factor,
                threshold=0.01)
    brc.fit(X)
    check_branching_factor(brc.root_, branching_factor)

    # Raises error when branching_factor is set to one.
    brc = Birch(n_clusters=None, branching_factor=1, threshold=0.01)
    assert_raises(ValueError, brc.fit, X)