embedding.py 文件源码

def spectral_embedding(mat, target_dim, gramian=True, discard_first=True):
    if discard_first:
        last = -1
        first = target_dim - last
    else:
        first = target_dim
        last = None
    if not gramian:
        mat = mat.dot(mat.T)
    eigvals, eigvecs = eigh(mat)

    sl = slice(-first, last)
    eigvecs = eigvecs[:, sl]
    eigvals_crop = eigvals[sl]
    Y = eigvecs.dot(np.diag(np.sqrt(eigvals_crop)))
    Y = Y[:, ::-1]

    variance_explaned(eigvals, eigvals_crop)
    return Y