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])
n_estimators=600, learning_rate=1) bdt_discrete = AdaBoostClassifier(DecisionTreeClassifier(max_depth=2), n_estimators=600, learning_rate=1.5, algorithm="SAMME") bdt_real.fit(X_train, y_train) bdt_discrete.fit(X_train, y_train) real_test_errors = [] discrete_test_errors = [] for real_test_predict, discrete_train_predict in zip( bdt_real.staged_predict(X_test), bdt_discrete.staged_predict(X_test)): real_test_errors.append(1. - accuracy_score(real_test_predict, y_test)) discrete_test_errors.append(1. - accuracy_score(discrete_train_predict, y_test)) n_trees_discrete = len(bdt_discrete) n_trees_real = len(bdt_real) # Boosting might terminate early, but the following arrays are always # n_estimators long. We crop them to the actual number of trees here: discrete_estimator_errors = bdt_discrete.estimator_errors_[:n_trees_discrete] real_estimator_errors = bdt_real.estimator_errors_[:n_trees_real] discrete_estimator_weights = bdt_discrete.estimator_weights_[:n_trees_discrete] plt.figure(figsize=(15, 5))
ada_real = AdaBoostClassifier(base_estimator=dt_stump, learning_rate=learning_rate, n_estimators=n_estimators, algorithm="SAMME.R") ada_real.fit(X_train, y_train) fig = plt.figure() ax = fig.add_subplot(111) ax.plot([1, n_estimators], [dt_stump_err] * 2, 'k-', label='Decision Stump Error') ax.plot([1, n_estimators], [dt_err] * 2, 'k--', label='Decision Tree Error') ada_discrete_err = np.zeros((n_estimators, )) for i, y_pred in enumerate(ada_discrete.staged_predict(X_test)): ada_discrete_err[i] = zero_one_loss(y_pred, y_test) ada_discrete_err_train = np.zeros((n_estimators, )) for i, y_pred in enumerate(ada_discrete.staged_predict(X_train)): ada_discrete_err_train[i] = zero_one_loss(y_pred, y_train) ada_real_err = np.zeros((n_estimators, )) for i, y_pred in enumerate(ada_real.staged_predict(X_test)): ada_real_err[i] = zero_one_loss(y_pred, y_test) ada_real_err_train = np.zeros((n_estimators, )) for i, y_pred in enumerate(ada_real.staged_predict(X_train)): ada_real_err_train[i] = zero_one_loss(y_pred, y_train) ax.plot(np.arange(n_estimators) + 1,
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])