test_bagging.py 文件源码

def test_oob_score_regression():
    # Check that oob prediction is a good estimation of the generalization
    # error.
    rng = check_random_state(0)
    X_train, X_test, y_train, y_test = train_test_split(boston.data,
                                                        boston.target,
                                                        random_state=rng)

    clf = BaggingRegressor(base_estimator=DecisionTreeRegressor(),
                           n_estimators=50,
                           bootstrap=True,
                           oob_score=True,
                           random_state=rng).fit(X_train, y_train)

    test_score = clf.score(X_test, y_test)

    assert_less(abs(test_score - clf.oob_score_), 0.1)

    # Test with few estimators
    assert_warns(UserWarning,
                 BaggingRegressor(base_estimator=DecisionTreeRegressor(),
                                  n_estimators=1,
                                  bootstrap=True,
                                  oob_score=True,
                                  random_state=rng).fit,
                 X_train,
                 y_train)