Python MultiOutputClassifier.predict_proba方法代码示例

# 需要导入模块: from sklearn.multioutput import MultiOutputClassifier [as 别名]
# 或者: from sklearn.multioutput.MultiOutputClassifier import predict_proba [as 别名]
def test_multi_output_predict_proba():
    sgd_linear_clf = SGDClassifier(random_state=1, max_iter=5, tol=1e-3)
    param = {'loss': ('hinge', 'log', 'modified_huber')}

    # inner function for custom scoring
    def custom_scorer(estimator, X, y):
        if hasattr(estimator, "predict_proba"):
            return 1.0
        else:
            return 0.0
    grid_clf = GridSearchCV(sgd_linear_clf, param_grid=param,
                            scoring=custom_scorer, cv=3, error_score=np.nan)
    multi_target_linear = MultiOutputClassifier(grid_clf)
    multi_target_linear.fit(X, y)

    multi_target_linear.predict_proba(X)

    # SGDClassifier defaults to loss='hinge' which is not a probabilistic
    # loss function; therefore it does not expose a predict_proba method
    sgd_linear_clf = SGDClassifier(random_state=1, max_iter=5, tol=1e-3)
    multi_target_linear = MultiOutputClassifier(sgd_linear_clf)
    multi_target_linear.fit(X, y)
    err_msg = "The base estimator should implement predict_proba method"
    with pytest.raises(ValueError, match=err_msg):
        multi_target_linear.predict_proba(X)

# 需要导入模块: from sklearn.multioutput import MultiOutputClassifier [as 别名]
# 或者: from sklearn.multioutput.MultiOutputClassifier import predict_proba [as 别名]
def test_multiclass_multioutput_estimator_predict_proba():
    seed = 542

    # make test deterministic
    rng = np.random.RandomState(seed)

    # random features
    X = rng.normal(size=(5, 5))

    # random labels
    y1 = np.array(['b', 'a', 'a', 'b', 'a']).reshape(5, 1)  # 2 classes
    y2 = np.array(['d', 'e', 'f', 'e', 'd']).reshape(5, 1)  # 3 classes

    Y = np.concatenate([y1, y2], axis=1)

    clf = MultiOutputClassifier(LogisticRegression(random_state=seed))

    clf.fit(X, Y)

    y_result = clf.predict_proba(X)
    y_actual = [np.array([[0.23481764, 0.76518236],
                          [0.67196072, 0.32803928],
                          [0.54681448, 0.45318552],
                          [0.34883923, 0.65116077],
                          [0.73687069, 0.26312931]]),
                np.array([[0.5171785, 0.23878628, 0.24403522],
                          [0.22141451, 0.64102704, 0.13755846],
                          [0.16751315, 0.18256843, 0.64991843],
                          [0.27357372, 0.55201592, 0.17441036],
                          [0.65745193, 0.26062899, 0.08191907]])]

    for i in range(len(y_actual)):
        assert_almost_equal(y_result[i], y_actual[i])

# 需要导入模块: from sklearn.multioutput import MultiOutputClassifier [as 别名]
# 或者: from sklearn.multioutput.MultiOutputClassifier import predict_proba [as 别名]
def test_multi_output_classification():
    # test if multi_target initializes correctly with base estimator and fit
    # assert predictions work as expected for predict, prodict_proba and score

    forest = RandomForestClassifier(n_estimators=10, random_state=1)
    multi_target_forest = MultiOutputClassifier(forest)

    # train the multi_target_forest and also get the predictions.
    multi_target_forest.fit(X, y)

    predictions = multi_target_forest.predict(X)
    assert_equal((n_samples, n_outputs), predictions.shape)

    predict_proba = multi_target_forest.predict_proba(X)

    assert len(predict_proba) == n_outputs
    for class_probabilities in predict_proba:
        assert_equal((n_samples, n_classes), class_probabilities.shape)

    assert_array_equal(np.argmax(np.dstack(predict_proba), axis=1),
                       predictions)

    # train the forest with each column and assert that predictions are equal
    for i in range(3):
        forest_ = clone(forest)  # create a clone with the same state
        forest_.fit(X, y[:, i])
        assert_equal(list(forest_.predict(X)), list(predictions[:, i]))
        assert_array_equal(list(forest_.predict_proba(X)),
                           list(predict_proba[i]))