decision_tree_binner.py 文件源码

def _calculate_noise_delta(tree, node_id):
    S, nS, S1, nS1, S2, nS2 = _get_variables_for_entropy_calculation(tree, node_id)

    return np.log2(np.power(3, nS) - 2) \
            - (nS * _calculate_entropy(S)
            - nS1 * _calculate_entropy(S1)
            - nS2 * _calculate_entropy(S2))