test_bagging.py 文件源码

def test_sparse_regression():
    # Check regression for various parameter settings on sparse input.
    rng = check_random_state(0)
    X_train, X_test, y_train, y_test = train_test_split(boston.data[:50],
                                                        boston.target[:50],
                                                        random_state=rng)

    class CustomSVR(SVR):
        """SVC variant that records the nature of the training set"""

        def fit(self, X, y):
            super(CustomSVR, self).fit(X, y)
            self.data_type_ = type(X)
            return self

    parameter_sets = [
        {"max_samples": 0.5,
         "max_features": 2,
         "bootstrap": True,
         "bootstrap_features": True},
        {"max_samples": 1.0,
         "max_features": 4,
         "bootstrap": True,
         "bootstrap_features": True},
        {"max_features": 2,
         "bootstrap": False,
         "bootstrap_features": True},
        {"max_samples": 0.5,
         "bootstrap": True,
         "bootstrap_features": False},
    ]

    for sparse_format in [csc_matrix, csr_matrix]:
        X_train_sparse = sparse_format(X_train)
        X_test_sparse = sparse_format(X_test)
        for params in parameter_sets:

            # Trained on sparse format
            sparse_classifier = BaggingRegressor(
                base_estimator=CustomSVR(),
                random_state=1,
                **params
            ).fit(X_train_sparse, y_train)
            sparse_results = sparse_classifier.predict(X_test_sparse)

            # Trained on dense format
            dense_results = BaggingRegressor(
                base_estimator=CustomSVR(),
                random_state=1,
                **params
            ).fit(X_train, y_train).predict(X_test)

            sparse_type = type(X_train_sparse)
            types = [i.data_type_ for i in sparse_classifier.estimators_]

            assert_array_equal(sparse_results, dense_results)
            assert all([t == sparse_type for t in types])
            assert_array_equal(sparse_results, dense_results)