decision_tree_binner.py 文件源码

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

    return _calculate_entropy(S) \
            - S1.sum() / S.sum() * _calculate_entropy(S1) \
            - S2.sum() / S.sum() * _calculate_entropy(S2)