def test_classification_toy(algorithm):
    # Check classification on a toy dataset.
    clf = AdaBoostClassifier(algorithm=algorithm, random_state=0)
    clf.fit(X, y_class)
    assert_array_equal(clf.predict(T), y_t_class)
    assert_array_equal(np.unique(np.asarray(y_t_class)), clf.classes_)
    assert clf.predict_proba(T).shape == (len(T), 2)
    assert clf.decision_function(T).shape == (len(T), )
def test_multidimensional_X():
    """
    Check that the AdaBoost estimators can work with n-dimensional
    data matrix
    """
    rng = np.random.RandomState(0)

    X = rng.randn(50, 3, 3)
    yc = rng.choice([0, 1], 50)
    yr = rng.randn(50)

    boost = AdaBoostClassifier(DummyClassifier(strategy='most_frequent'))
    boost.fit(X, yc)
    boost.predict(X)
    boost.predict_proba(X)

    boost = AdaBoostRegressor(DummyRegressor())
    boost.fit(X, yr)
    boost.predict(X)
def test_staged_predict(algorithm):
    # Check staged predictions.
    rng = np.random.RandomState(0)
    iris_weights = rng.randint(10, size=iris.target.shape)
    boston_weights = rng.randint(10, size=boston.target.shape)

    clf = AdaBoostClassifier(algorithm=algorithm, n_estimators=10)
    clf.fit(iris.data, iris.target, sample_weight=iris_weights)

    predictions = clf.predict(iris.data)
    staged_predictions = [p for p in clf.staged_predict(iris.data)]
    proba = clf.predict_proba(iris.data)
    staged_probas = [p for p in clf.staged_predict_proba(iris.data)]
    score = clf.score(iris.data, iris.target, sample_weight=iris_weights)
    staged_scores = [
        s for s in clf.staged_score(
            iris.data, iris.target, sample_weight=iris_weights)
    ]

    assert len(staged_predictions) == 10
    assert_array_almost_equal(predictions, staged_predictions[-1])
    assert len(staged_probas) == 10
    assert_array_almost_equal(proba, staged_probas[-1])
    assert len(staged_scores) == 10
    assert_array_almost_equal(score, staged_scores[-1])

    # AdaBoost regression
    clf = AdaBoostRegressor(n_estimators=10, random_state=0)
    clf.fit(boston.data, boston.target, sample_weight=boston_weights)

    predictions = clf.predict(boston.data)
    staged_predictions = [p for p in clf.staged_predict(boston.data)]
    score = clf.score(boston.data, boston.target, sample_weight=boston_weights)
    staged_scores = [
        s for s in clf.staged_score(
            boston.data, boston.target, sample_weight=boston_weights)
    ]

    assert len(staged_predictions) == 10
    assert_array_almost_equal(predictions, staged_predictions[-1])
    assert len(staged_scores) == 10
    assert_array_almost_equal(score, staged_scores[-1])
def test_adaboost_consistent_predict(algorithm):
    # check that predict_proba and predict give consistent results
    # regression test for:
    # https://github.com/scikit-learn/scikit-learn/issues/14084
    X_train, X_test, y_train, y_test = train_test_split(
        *datasets.load_digits(return_X_y=True), random_state=42)
    model = AdaBoostClassifier(algorithm=algorithm, random_state=42)
    model.fit(X_train, y_train)

    assert_array_equal(np.argmax(model.predict_proba(X_test), axis=1),
                       model.predict(X_test))
def test_sparse_classification():
    # Check classification with sparse input.

    class CustomSVC(SVC):
        """SVC variant that records the nature of the training set."""
        def fit(self, X, y, sample_weight=None):
            """Modification on fit caries data type for later verification."""
            super().fit(X, y, sample_weight=sample_weight)
            self.data_type_ = type(X)
            return self

    X, y = datasets.make_multilabel_classification(n_classes=1,
                                                   n_samples=15,
                                                   n_features=5,
                                                   random_state=42)
    # Flatten y to a 1d array
    y = np.ravel(y)

    X_train, X_test, y_train, y_test = train_test_split(X, y, random_state=0)

    for sparse_format in [
            csc_matrix, csr_matrix, lil_matrix, coo_matrix, dok_matrix
    ]:
        X_train_sparse = sparse_format(X_train)
        X_test_sparse = sparse_format(X_test)

        # Trained on sparse format
        sparse_classifier = AdaBoostClassifier(
            base_estimator=CustomSVC(probability=True),
            random_state=1,
            algorithm="SAMME").fit(X_train_sparse, y_train)

        # Trained on dense format
        dense_classifier = AdaBoostClassifier(
            base_estimator=CustomSVC(probability=True),
            random_state=1,
            algorithm="SAMME").fit(X_train, y_train)

        # predict
        sparse_results = sparse_classifier.predict(X_test_sparse)
        dense_results = dense_classifier.predict(X_test)
        assert_array_equal(sparse_results, dense_results)

        # decision_function
        sparse_results = sparse_classifier.decision_function(X_test_sparse)
        dense_results = dense_classifier.decision_function(X_test)
        assert_array_almost_equal(sparse_results, dense_results)

        # predict_log_proba
        sparse_results = sparse_classifier.predict_log_proba(X_test_sparse)
        dense_results = dense_classifier.predict_log_proba(X_test)
        assert_array_almost_equal(sparse_results, dense_results)

        # predict_proba
        sparse_results = sparse_classifier.predict_proba(X_test_sparse)
        dense_results = dense_classifier.predict_proba(X_test)
        assert_array_almost_equal(sparse_results, dense_results)

        # score
        sparse_results = sparse_classifier.score(X_test_sparse, y_test)
        dense_results = dense_classifier.score(X_test, y_test)
        assert_array_almost_equal(sparse_results, dense_results)

        # staged_decision_function
        sparse_results = sparse_classifier.staged_decision_function(
            X_test_sparse)
        dense_results = dense_classifier.staged_decision_function(X_test)
        for sprase_res, dense_res in zip(sparse_results, dense_results):
            assert_array_almost_equal(sprase_res, dense_res)

        # staged_predict
        sparse_results = sparse_classifier.staged_predict(X_test_sparse)
        dense_results = dense_classifier.staged_predict(X_test)
        for sprase_res, dense_res in zip(sparse_results, dense_results):
            assert_array_equal(sprase_res, dense_res)

        # staged_predict_proba
        sparse_results = sparse_classifier.staged_predict_proba(X_test_sparse)
        dense_results = dense_classifier.staged_predict_proba(X_test)
        for sprase_res, dense_res in zip(sparse_results, dense_results):
            assert_array_almost_equal(sprase_res, dense_res)

        # staged_score
        sparse_results = sparse_classifier.staged_score(X_test_sparse, y_test)
        dense_results = dense_classifier.staged_score(X_test, y_test)
        for sprase_res, dense_res in zip(sparse_results, dense_results):
            assert_array_equal(sprase_res, dense_res)

        # Verify sparsity of data is maintained during training
        types = [i.data_type_ for i in sparse_classifier.estimators_]

        assert all([(t == csc_matrix or t == csr_matrix) for t in types])