plotting.py 文件源码

def layout_tree(correlation):
    """Layout tree for visualization with e.g. matplotlib.

    Args:
        correlation: A [V, V]-shaped numpy array of latent correlations.

    Returns:
        A [V, 3]-shaped numpy array of spectral positions of vertices.
    """
    assert len(correlation.shape) == 2
    assert correlation.shape[0] == correlation.shape[1]
    assert correlation.dtype == np.float32

    laplacian = -correlation
    np.fill_diagonal(laplacian, 0)
    np.fill_diagonal(laplacian, -laplacian.sum(axis=0))
    evals, evects = scipy.linalg.eigh(laplacian, eigvals=[1, 2, 3])
    assert np.all(evals > 0)
    assert evects.shape[1] == 3
    return evects