test_gradient_boosting.py 文件源码

def check_classification_toy(presort, loss):
    # Check classification on a toy dataset.
    clf = GradientBoostingClassifier(loss=loss, n_estimators=10,
                                     random_state=1, presort=presort)

    assert_raises(ValueError, clf.predict, T)

    clf.fit(X, y)
    assert_array_equal(clf.predict(T), true_result)
    assert_equal(10, len(clf.estimators_))

    deviance_decrease = (clf.train_score_[:-1] - clf.train_score_[1:])
    assert_true(np.any(deviance_decrease >= 0.0))

    leaves = clf.apply(X)
    assert_equal(leaves.shape, (6, 10, 1))