def test_thresholded_scorers():
# Test scorers that take thresholds.
X, y = make_blobs(random_state=0, centers=2)
X_train, X_test, y_train, y_test = train_test_split(X, y, random_state=0)
clf = LogisticRegression(random_state=0)
clf.fit(X_train, y_train)
score1 = get_scorer('roc_auc')(clf, X_test, y_test)
score2 = roc_auc_score(y_test, clf.decision_function(X_test))
score3 = roc_auc_score(y_test, clf.predict_proba(X_test)[:, 1])
assert_almost_equal(score1, score2)
assert_almost_equal(score1, score3)
logscore = get_scorer('neg_log_loss')(clf, X_test, y_test)
logloss = log_loss(y_test, clf.predict_proba(X_test))
assert_almost_equal(-logscore, logloss)
# same for an estimator without decision_function
clf = DecisionTreeClassifier()
clf.fit(X_train, y_train)
score1 = get_scorer('roc_auc')(clf, X_test, y_test)
score2 = roc_auc_score(y_test, clf.predict_proba(X_test)[:, 1])
assert_almost_equal(score1, score2)
# test with a regressor (no decision_function)
reg = DecisionTreeRegressor()
reg.fit(X_train, y_train)
score1 = get_scorer('roc_auc')(reg, X_test, y_test)
score2 = roc_auc_score(y_test, reg.predict(X_test))
assert_almost_equal(score1, score2)
# Test that an exception is raised on more than two classes
X, y = make_blobs(random_state=0, centers=3)
X_train, X_test, y_train, y_test = train_test_split(X, y, random_state=0)
clf.fit(X_train, y_train)
with pytest.raises(ValueError, match="multiclass format is not supported"):
get_scorer('roc_auc')(clf, X_test, y_test)
# test error is raised with a single class present in model
# (predict_proba shape is not suitable for binary auc)
X, y = make_blobs(random_state=0, centers=2)
X_train, X_test, y_train, y_test = train_test_split(X, y, random_state=0)
clf = DecisionTreeClassifier()
clf.fit(X_train, np.zeros_like(y_train))
with pytest.raises(ValueError, match="need classifier with two classes"):
get_scorer('roc_auc')(clf, X_test, y_test)
# for proba scorers
with pytest.raises(ValueError, match="need classifier with two classes"):
get_scorer('neg_log_loss')(clf, X_test, y_test)
def test_predict_sparse_callable_kernel():
# This is a non-regression test for #15866
# Custom sparse kernel (top-K RBF)
def topk_rbf(X, Y=None, n_neighbors=10, gamma=1e-5):
nn = NearestNeighbors(n_neighbors=10, metric='euclidean', n_jobs=-1)
nn.fit(X)
W = -1 * nn.kneighbors_graph(Y, mode='distance').power(2) * gamma
np.exp(W.data, out=W.data)
assert issparse(W)
return W.T
n_classes = 4
n_samples = 500
n_test = 10
X, y = make_classification(n_classes=n_classes,
n_samples=n_samples,
n_features=20,
n_informative=20,
n_redundant=0,
n_repeated=0,
random_state=0)
X_train, X_test, y_train, y_test = train_test_split(X,
y,
test_size=n_test,
random_state=0)
model = label_propagation.LabelSpreading(kernel=topk_rbf)
model.fit(X_train, y_train)
assert model.score(X_test, y_test) >= 0.9
model = label_propagation.LabelPropagation(kernel=topk_rbf)
model.fit(X_train, y_train)
assert model.score(X_test, y_test) >= 0.9
def test_oob_score_regression():
# Check that oob prediction is a good estimation of the generalization
# error.
rng = check_random_state(0)
X_train, X_test, y_train, y_test = train_test_split(boston.data,
boston.target,
random_state=rng)
clf = BaggingRegressor(base_estimator=DecisionTreeRegressor(),
n_estimators=50,
bootstrap=True,
oob_score=True,
random_state=rng).fit(X_train, y_train)
test_score = clf.score(X_test, y_test)
assert abs(test_score - clf.oob_score_) < 0.1
# Test with few estimators
assert_warns(
UserWarning,
BaggingRegressor(base_estimator=DecisionTreeRegressor(),
n_estimators=1,
bootstrap=True,
oob_score=True,
random_state=rng).fit, X_train, y_train)
def test_oob_score_classification():
# Check that oob prediction is a good estimation of the generalization
# error.
rng = check_random_state(0)
X_train, X_test, y_train, y_test = train_test_split(iris.data,
iris.target,
random_state=rng)
for base_estimator in [DecisionTreeClassifier(), SVC()]:
clf = BaggingClassifier(base_estimator=base_estimator,
n_estimators=100,
bootstrap=True,
oob_score=True,
random_state=rng).fit(X_train, y_train)
test_score = clf.score(X_test, y_test)
assert abs(test_score - clf.oob_score_) < 0.1
# Test with few estimators
assert_warns(
UserWarning,
BaggingClassifier(base_estimator=base_estimator,
n_estimators=1,
bootstrap=True,
oob_score=True,
random_state=rng).fit, X_train, y_train)
def test_probability():
# Predict probabilities.
rng = check_random_state(0)
X_train, X_test, y_train, y_test = train_test_split(iris.data,
iris.target,
random_state=rng)
with np.errstate(divide="ignore", invalid="ignore"):
# Normal case
ensemble = BaggingClassifier(base_estimator=DecisionTreeClassifier(),
random_state=rng).fit(X_train, y_train)
assert_array_almost_equal(
np.sum(ensemble.predict_proba(X_test), axis=1),
np.ones(len(X_test)))
assert_array_almost_equal(ensemble.predict_proba(X_test),
np.exp(ensemble.predict_log_proba(X_test)))
# Degenerate case, where some classes are missing
ensemble = BaggingClassifier(base_estimator=LogisticRegression(),
random_state=rng,
max_samples=5).fit(X_train, y_train)
assert_array_almost_equal(
np.sum(ensemble.predict_proba(X_test), axis=1),
np.ones(len(X_test)))
assert_array_almost_equal(ensemble.predict_proba(X_test),
np.exp(ensemble.predict_log_proba(X_test)))
def test_iforest_sparse():
"""Check IForest 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)
grid = ParameterGrid({
"max_samples": [0.5, 1.0],
"bootstrap": [True, 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 grid:
# Trained on sparse format
sparse_classifier = IsolationForest(n_estimators=10,
random_state=1,
**params).fit(X_train_sparse)
sparse_results = sparse_classifier.predict(X_test_sparse)
# Trained on dense format
dense_classifier = IsolationForest(n_estimators=10,
random_state=1,
**params).fit(X_train)
dense_results = dense_classifier.predict(X_test)
assert_array_equal(sparse_results, dense_results)
def test_weights_regressor():
"""Check weighted average regression prediction on boston dataset."""
reg1 = DummyRegressor(strategy='mean')
reg2 = DummyRegressor(strategy='median')
reg3 = DummyRegressor(strategy='quantile', quantile=.2)
ereg = VotingRegressor([('mean', reg1), ('median', reg2),
('quantile', reg3)],
weights=[1, 2, 10])
X_r_train, X_r_test, y_r_train, y_r_test = \
train_test_split(X_r, y_r, test_size=.25)
reg1_pred = reg1.fit(X_r_train, y_r_train).predict(X_r_test)
reg2_pred = reg2.fit(X_r_train, y_r_train).predict(X_r_test)
reg3_pred = reg3.fit(X_r_train, y_r_train).predict(X_r_test)
ereg_pred = ereg.fit(X_r_train, y_r_train).predict(X_r_test)
avg = np.average(np.asarray([reg1_pred, reg2_pred, reg3_pred]),
axis=0,
weights=[1, 2, 10])
assert_almost_equal(ereg_pred, avg, decimal=2)
ereg_weights_none = VotingRegressor([('mean', reg1), ('median', reg2),
('quantile', reg3)],
weights=None)
ereg_weights_equal = VotingRegressor([('mean', reg1), ('median', reg2),
('quantile', reg3)],
weights=[1, 1, 1])
ereg_weights_none.fit(X_r_train, y_r_train)
ereg_weights_equal.fit(X_r_train, y_r_train)
ereg_none_pred = ereg_weights_none.predict(X_r_test)
ereg_equal_pred = ereg_weights_equal.predict(X_r_test)
assert_almost_equal(ereg_none_pred, ereg_equal_pred, decimal=2)
def test_stacking_with_sample_weight(stacker, X, y):
# check that sample weights has an influence on the fitting
# note: ConvergenceWarning are catch since we are not worrying about the
# convergence here
n_half_samples = len(y) // 2
total_sample_weight = np.array([0.1] * n_half_samples + [0.9] *
(len(y) - n_half_samples))
X_train, X_test, y_train, _, sample_weight_train, _ = train_test_split(
X, y, total_sample_weight, random_state=42)
with ignore_warnings(category=ConvergenceWarning):
stacker.fit(X_train, y_train)
y_pred_no_weight = stacker.predict(X_test)
with ignore_warnings(category=ConvergenceWarning):
stacker.fit(X_train, y_train, sample_weight=np.ones(y_train.shape))
y_pred_unit_weight = stacker.predict(X_test)
assert_allclose(y_pred_no_weight, y_pred_unit_weight)
with ignore_warnings(category=ConvergenceWarning):
stacker.fit(X_train, y_train, sample_weight=sample_weight_train)
y_pred_biased = stacker.predict(X_test)
assert np.abs(y_pred_no_weight - y_pred_biased).sum() > 0
def test_decision_function_shape():
# check that decision_function_shape='ovr' gives
# correct shape and is consistent with predict
clf = svm.SVC(kernel='linear', C=0.1,
decision_function_shape='ovr').fit(iris.data, iris.target)
dec = clf.decision_function(iris.data)
assert dec.shape == (len(iris.data), 3)
assert_array_equal(clf.predict(iris.data), np.argmax(dec, axis=1))
# with five classes:
X, y = make_blobs(n_samples=80, centers=5, random_state=0)
X_train, X_test, y_train, y_test = train_test_split(X, y, random_state=0)
clf = svm.SVC(kernel='linear', C=0.1,
decision_function_shape='ovr').fit(X_train, y_train)
dec = clf.decision_function(X_test)
assert dec.shape == (len(X_test), 5)
assert_array_equal(clf.predict(X_test), np.argmax(dec, axis=1))
# check shape of ovo_decition_function=True
clf = svm.SVC(kernel='linear', C=0.1,
decision_function_shape='ovo').fit(X_train, y_train)
dec = clf.decision_function(X_train)
assert dec.shape == (len(X_train), 10)
def test_stacking_regressor_diabetes(cv, final_estimator, predict_params,
passthrough):
# prescale the data to avoid convergence warning without using a pipeline
# for later assert
X_train, X_test, y_train, _ = train_test_split(scale(X_diabetes),
y_diabetes,
random_state=42)
estimators = [('lr', LinearRegression()), ('svr', LinearSVR())]
reg = StackingRegressor(estimators=estimators,
final_estimator=final_estimator,
cv=cv,
passthrough=passthrough)
reg.fit(X_train, y_train)
result = reg.predict(X_test, **predict_params)
expected_result_length = 2 if predict_params else 1
if predict_params:
assert len(result) == expected_result_length
X_trans = reg.transform(X_test)
expected_column_count = 12 if passthrough else 2
assert X_trans.shape[1] == expected_column_count
if passthrough:
assert_allclose(X_test, X_trans[:, -10:])
reg.set_params(lr='drop')
reg.fit(X_train, y_train)
reg.predict(X_test)
X_trans = reg.transform(X_test)
expected_column_count_drop = 11 if passthrough else 1
assert X_trans.shape[1] == expected_column_count_drop
if passthrough:
assert_allclose(X_test, X_trans[:, -10:])
def test_count_vectorizer_pipeline_grid_selection():
# raw documents
data = JUNK_FOOD_DOCS + NOTJUNK_FOOD_DOCS
# label junk food as -1, the others as +1
target = [-1] * len(JUNK_FOOD_DOCS) + [1] * len(NOTJUNK_FOOD_DOCS)
# split the dataset for model development and final evaluation
train_data, test_data, target_train, target_test = train_test_split(
data, target, test_size=.2, random_state=0)
pipeline = Pipeline([('vect', CountVectorizer()),
('svc', LinearSVC())])
parameters = {
'vect__ngram_range': [(1, 1), (1, 2)],
'svc__loss': ('hinge', 'squared_hinge')
}
# find the best parameters for both the feature extraction and the
# classifier
grid_search = GridSearchCV(pipeline, parameters, n_jobs=1, cv=3)
# Check that the best model found by grid search is 100% correct on the
# held out evaluation set.
pred = grid_search.fit(train_data, target_train).predict(test_data)
assert_array_equal(pred, target_test)
# on this toy dataset bigram representation which is used in the last of
# the grid_search is considered the best estimator since they all converge
# to 100% accuracy models
assert grid_search.best_score_ == 1.0
best_vectorizer = grid_search.best_estimator_.named_steps['vect']
assert best_vectorizer.ngram_range == (1, 1)
def test_classification():
# Check classification for various parameter settings.
rng = check_random_state(0)
X_train, X_test, y_train, y_test = train_test_split(iris.data,
iris.target,
random_state=rng)
grid = ParameterGrid({
"max_samples": [0.5, 1.0],
"max_features": [1, 2, 4],
"bootstrap": [True, False],
"bootstrap_features": [True, False]
})
for base_estimator in [
None,
DummyClassifier(),
Perceptron(),
DecisionTreeClassifier(),
KNeighborsClassifier(),
SVC()
]:
for params in grid:
BaggingClassifier(base_estimator=base_estimator,
random_state=rng,
**params).fit(X_train, y_train).predict(X_test)
def test_boston_dataset(n_bins):
X, y = load_boston(return_X_y=True)
X_train, X_test, y_train, y_test = train_test_split(X, y, random_state=42)
mapper = _BinMapper(n_bins=n_bins, random_state=42)
X_train_binned = mapper.fit_transform(X_train)
# Init gradients and hessians to that of least squares loss
gradients = -y_train.astype(G_H_DTYPE)
hessians = np.ones(1, dtype=G_H_DTYPE)
min_samples_leaf = 8
max_leaf_nodes = 31
grower = TreeGrower(X_train_binned,
gradients,
hessians,
min_samples_leaf=min_samples_leaf,
max_leaf_nodes=max_leaf_nodes,
n_bins=n_bins,
n_bins_non_missing=mapper.n_bins_non_missing_)
grower.grow()
predictor = grower.make_predictor(bin_thresholds=mapper.bin_thresholds_)
assert r2_score(y_train, predictor.predict(X_train)) > 0.85
assert r2_score(y_test, predictor.predict(X_test)) > 0.70
def test_lars_path_readonly_data():
# When using automated memory mapping on large input, the
# fold data is in read-only mode
# This is a non-regression test for:
# https://github.com/scikit-learn/scikit-learn/issues/4597
splitted_data = train_test_split(X, y, random_state=42)
with TempMemmap(splitted_data) as (X_train, X_test, y_train, y_test):
# The following should not fail despite copy=False
_lars_path_residues(X_train, y_train, X_test, y_test, copy=False)
def test_deprecated_scorer():
X, y = make_blobs(random_state=0, centers=2)
X_train, X_test, y_train, y_test = train_test_split(X, y, random_state=0)
clf = DecisionTreeClassifier()
clf.fit(X_train, y_train)
deprecated_scorer = get_scorer('brier_score_loss')
with pytest.warns(FutureWarning):
deprecated_scorer(clf, X_test, y_test)
def test_iforest_subsampled_features():
# It tests non-regression for #5732 which failed at predict.
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)
clf = IsolationForest(max_features=0.8)
clf.fit(X_train, y_train)
clf.predict(X_test)
def test_base_estimator():
# Check base_estimator and its default values.
rng = check_random_state(0)
# Classification
X_train, X_test, y_train, y_test = train_test_split(iris.data,
iris.target,
random_state=rng)
ensemble = BaggingClassifier(None, n_jobs=3,
random_state=0).fit(X_train, y_train)
assert isinstance(ensemble.base_estimator_, DecisionTreeClassifier)
ensemble = BaggingClassifier(DecisionTreeClassifier(),
n_jobs=3,
random_state=0).fit(X_train, y_train)
assert isinstance(ensemble.base_estimator_, DecisionTreeClassifier)
ensemble = BaggingClassifier(Perceptron(), n_jobs=3,
random_state=0).fit(X_train, y_train)
assert isinstance(ensemble.base_estimator_, Perceptron)
# Regression
X_train, X_test, y_train, y_test = train_test_split(boston.data,
boston.target,
random_state=rng)
ensemble = BaggingRegressor(None, n_jobs=3,
random_state=0).fit(X_train, y_train)
assert isinstance(ensemble.base_estimator_, DecisionTreeRegressor)
ensemble = BaggingRegressor(DecisionTreeRegressor(),
n_jobs=3,
random_state=0).fit(X_train, y_train)
assert isinstance(ensemble.base_estimator_, DecisionTreeRegressor)
ensemble = BaggingRegressor(SVR(), n_jobs=3,
random_state=0).fit(X_train, y_train)
assert isinstance(ensemble.base_estimator_, SVR)
def test_same_predictions_classification(seed, min_samples_leaf, n_samples,
max_leaf_nodes):
# Same as test_same_predictions_regression but for classification
rng = np.random.RandomState(seed=seed)
n_samples = n_samples
max_iter = 1
max_bins = 255
X, y = make_classification(n_samples=n_samples,
n_classes=2,
n_features=5,
n_informative=5,
n_redundant=0,
random_state=0)
if n_samples > 255:
# bin data and convert it to float32 so that the estimator doesn't
# treat it as pre-binned
X = _BinMapper(n_bins=max_bins + 1).fit_transform(X).astype(np.float32)
X_train, X_test, y_train, y_test = train_test_split(X, y, random_state=rng)
est_sklearn = HistGradientBoostingClassifier(
loss='binary_crossentropy',
max_iter=max_iter,
max_bins=max_bins,
learning_rate=1,
n_iter_no_change=None,
min_samples_leaf=min_samples_leaf,
max_leaf_nodes=max_leaf_nodes)
est_lightgbm = get_equivalent_estimator(est_sklearn, lib='lightgbm')
est_lightgbm.fit(X_train, y_train)
est_sklearn.fit(X_train, y_train)
# We need X to be treated an numerical data, not pre-binned data.
X_train, X_test = X_train.astype(np.float32), X_test.astype(np.float32)
pred_lightgbm = est_lightgbm.predict(X_train)
pred_sklearn = est_sklearn.predict(X_train)
assert np.mean(pred_sklearn == pred_lightgbm) > .89
acc_lightgbm = accuracy_score(y_train, pred_lightgbm)
acc_sklearn = accuracy_score(y_train, pred_sklearn)
np.testing.assert_almost_equal(acc_lightgbm, acc_sklearn)
if max_leaf_nodes < 10 and n_samples >= 1000:
pred_lightgbm = est_lightgbm.predict(X_test)
pred_sklearn = est_sklearn.predict(X_test)
assert np.mean(pred_sklearn == pred_lightgbm) > .89
acc_lightgbm = accuracy_score(y_test, pred_lightgbm)
acc_sklearn = accuracy_score(y_test, pred_sklearn)
np.testing.assert_almost_equal(acc_lightgbm, acc_sklearn, decimal=2)
def test_supervised_cluster_scorers():
# Test clustering scorers against gold standard labeling.
X, y = make_blobs(random_state=0, centers=2)
X_train, X_test, y_train, y_test = train_test_split(X, y, random_state=0)
km = KMeans(n_clusters=3)
km.fit(X_train)
for name in CLUSTER_SCORERS:
score1 = get_scorer(name)(km, X_test, y_test)
score2 = getattr(cluster_module, name)(y_test, km.predict(X_test))
assert_almost_equal(score1, score2)
def test_regression_scorers():
# Test regression scorers.
diabetes = load_diabetes()
X, y = diabetes.data, diabetes.target
X_train, X_test, y_train, y_test = train_test_split(X, y, random_state=0)
clf = Ridge()
clf.fit(X_train, y_train)
score1 = get_scorer('r2')(clf, X_test, y_test)
score2 = r2_score(y_test, clf.predict(X_test))
assert_almost_equal(score1, score2)
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_parallel_classification():
# Check parallel classification.
rng = check_random_state(0)
# Classification
X_train, X_test, y_train, y_test = train_test_split(iris.data,
iris.target,
random_state=rng)
ensemble = BaggingClassifier(DecisionTreeClassifier(),
n_jobs=3,
random_state=0).fit(X_train, y_train)
# predict_proba
ensemble.set_params(n_jobs=1)
y1 = ensemble.predict_proba(X_test)
ensemble.set_params(n_jobs=2)
y2 = ensemble.predict_proba(X_test)
assert_array_almost_equal(y1, y2)
ensemble = BaggingClassifier(DecisionTreeClassifier(),
n_jobs=1,
random_state=0).fit(X_train, y_train)
y3 = ensemble.predict_proba(X_test)
assert_array_almost_equal(y1, y3)
# decision_function
ensemble = BaggingClassifier(SVC(decision_function_shape='ovr'),
n_jobs=3,
random_state=0).fit(X_train, y_train)
ensemble.set_params(n_jobs=1)
decisions1 = ensemble.decision_function(X_test)
ensemble.set_params(n_jobs=2)
decisions2 = ensemble.decision_function(X_test)
assert_array_almost_equal(decisions1, decisions2)
X_err = np.hstack((X_test, np.zeros((X_test.shape[0], 1))))
assert_raise_message(
ValueError, "Number of features of the model "
"must match the input. Model n_features is {0} "
"and input n_features is {1} "
"".format(X_test.shape[1], X_err.shape[1]), ensemble.decision_function,
X_err)
ensemble = BaggingClassifier(SVC(decision_function_shape='ovr'),
n_jobs=1,
random_state=0).fit(X_train, y_train)
decisions3 = ensemble.decision_function(X_test)
assert_array_almost_equal(decisions1, decisions3)
def test_single_estimator():
# Check singleton ensembles.
rng = check_random_state(0)
X_train, X_test, y_train, y_test = train_test_split(boston.data,
boston.target,
random_state=rng)
clf1 = BaggingRegressor(base_estimator=KNeighborsRegressor(),
n_estimators=1,
bootstrap=False,
bootstrap_features=False,
random_state=rng).fit(X_train, y_train)
clf2 = KNeighborsRegressor().fit(X_train, y_train)
assert_array_almost_equal(clf1.predict(X_test), clf2.predict(X_test))
def test_sparse_regression():
# Check regression with sparse input.
class CustomSVR(SVR):
"""SVR 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_regression(n_samples=15,
n_features=50,
n_targets=1,
random_state=42)
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 = AdaBoostRegressor(base_estimator=CustomSVR(),
random_state=1).fit(
X_train_sparse, y_train)
# Trained on dense format
dense_classifier = dense_results = AdaBoostRegressor(
base_estimator=CustomSVR(), random_state=1).fit(X_train, y_train)
# predict
sparse_results = sparse_classifier.predict(X_test_sparse)
dense_results = dense_classifier.predict(X_test)
assert_array_almost_equal(sparse_results, dense_results)
# 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_almost_equal(sprase_res, dense_res)
types = [i.data_type_ for i in sparse_classifier.estimators_]
assert all([(t == csc_matrix or t == csr_matrix) for t in types])
def test_stacking_classifier_sparse_passthrough(fmt):
# Check passthrough behavior on a sparse X matrix
X_train, X_test, y_train, _ = train_test_split(sparse.coo_matrix(
scale(X_iris)).asformat(fmt),
y_iris,
random_state=42)
estimators = [('lr', LogisticRegression()), ('svc', LinearSVC())]
rf = RandomForestClassifier(n_estimators=10, random_state=42)
clf = StackingClassifier(estimators=estimators,
final_estimator=rf,
cv=5,
passthrough=True)
clf.fit(X_train, y_train)
X_trans = clf.transform(X_test)
assert_allclose_dense_sparse(X_test, X_trans[:, -4:])
assert sparse.issparse(X_trans)
assert X_test.format == X_trans.format
def test_warm_start_equal_n_estimators():
# Test that nothing happens when fitting without increasing n_estimators
X, y = make_hastie_10_2(n_samples=20, random_state=1)
X_train, X_test, y_train, y_test = train_test_split(X, y, random_state=43)
clf = BaggingClassifier(n_estimators=5, warm_start=True, random_state=83)
clf.fit(X_train, y_train)
y_pred = clf.predict(X_test)
# modify X to nonsense values, this should not change anything
X_train += 1.
assert_warns_message(
UserWarning,
"Warm-start fitting without increasing n_estimators does not", clf.fit,
X_train, y_train)
assert_array_equal(y_pred, clf.predict(X_test))
def test_scorer_sample_weight():
# Test that scorers support sample_weight or raise sensible errors
# Unlike the metrics invariance test, in the scorer case it's harder
# to ensure that, on the classifier output, weighted and unweighted
# scores really should be unequal.
X, y = make_classification(random_state=0)
_, y_ml = make_multilabel_classification(n_samples=X.shape[0],
random_state=0)
split = train_test_split(X, y, y_ml, random_state=0)
X_train, X_test, y_train, y_test, y_ml_train, y_ml_test = split
sample_weight = np.ones_like(y_test)
sample_weight[:10] = 0
# get sensible estimators for each metric
estimator = _make_estimators(X_train, y_train, y_ml_train)
for name, scorer in SCORERS.items():
if name in MULTILABEL_ONLY_SCORERS:
target = y_ml_test
else:
target = y_test
if name in REQUIRE_POSITIVE_Y_SCORERS:
target = _require_positive_y(target)
try:
weighted = scorer(estimator[name], X_test, target,
sample_weight=sample_weight)
ignored = scorer(estimator[name], X_test[10:], target[10:])
unweighted = scorer(estimator[name], X_test, target)
assert weighted != unweighted, (
"scorer {0} behaves identically when "
"called with sample weights: {1} vs "
"{2}".format(name, weighted, unweighted))
assert_almost_equal(weighted, ignored,
err_msg="scorer {0} behaves differently when "
"ignoring samples and setting sample_weight to"
" 0: {1} vs {2}".format(name, weighted,
ignored))
except TypeError as e:
assert "sample_weight" in str(e), (
"scorer {0} raises unhelpful exception when called "
"with sample weights: {1}".format(name, str(e)))
def test_stacking_regressor_drop_estimator():
# prescale the data to avoid convergence warning without using a pipeline
# for later assert
X_train, X_test, y_train, _ = train_test_split(scale(X_diabetes),
y_diabetes,
random_state=42)
estimators = [('lr', 'drop'), ('svr', LinearSVR(random_state=0))]
rf = RandomForestRegressor(n_estimators=10, random_state=42)
reg = StackingRegressor(estimators=[('svr', LinearSVR(random_state=0))],
final_estimator=rf,
cv=5)
reg_drop = StackingRegressor(estimators=estimators,
final_estimator=rf,
cv=5)
reg.fit(X_train, y_train)
reg_drop.fit(X_train, y_train)
assert_allclose(reg.predict(X_test), reg_drop.predict(X_test))
assert_allclose(reg.transform(X_test), reg_drop.transform(X_test))
def test_classification_scores():
# Test classification scorers.
X, y = make_blobs(random_state=0, centers=2)
X_train, X_test, y_train, y_test = train_test_split(X, y, random_state=0)
clf = LinearSVC(random_state=0)
clf.fit(X_train, y_train)
for prefix, metric in [('f1', f1_score), ('precision', precision_score),
('recall', recall_score),
('jaccard', jaccard_score)]:
score1 = get_scorer('%s_weighted' % prefix)(clf, X_test, y_test)
score2 = metric(y_test, clf.predict(X_test), pos_label=None,
average='weighted')
assert_almost_equal(score1, score2)
score1 = get_scorer('%s_macro' % prefix)(clf, X_test, y_test)
score2 = metric(y_test, clf.predict(X_test), pos_label=None,
average='macro')
assert_almost_equal(score1, score2)
score1 = get_scorer('%s_micro' % prefix)(clf, X_test, y_test)
score2 = metric(y_test, clf.predict(X_test), pos_label=None,
average='micro')
assert_almost_equal(score1, score2)
score1 = get_scorer('%s' % prefix)(clf, X_test, y_test)
score2 = metric(y_test, clf.predict(X_test), pos_label=1)
assert_almost_equal(score1, score2)
# test fbeta score that takes an argument
scorer = make_scorer(fbeta_score, beta=2)
score1 = scorer(clf, X_test, y_test)
score2 = fbeta_score(y_test, clf.predict(X_test), beta=2)
assert_almost_equal(score1, score2)
# test that custom scorer can be pickled
unpickled_scorer = pickle.loads(pickle.dumps(scorer))
score3 = unpickled_scorer(clf, X_test, y_test)
assert_almost_equal(score1, score3)
# smoke test the repr:
repr(fbeta_score)
def test_iforest_parallel_regression():
"""Check parallel regression."""
rng = check_random_state(0)
X_train, X_test, y_train, y_test = train_test_split(boston.data,
boston.target,
random_state=rng)
ensemble = IsolationForest(n_jobs=3, random_state=0).fit(X_train)
ensemble.set_params(n_jobs=1)
y1 = ensemble.predict(X_test)
ensemble.set_params(n_jobs=2)
y2 = ensemble.predict(X_test)
assert_array_almost_equal(y1, y2)
ensemble = IsolationForest(n_jobs=1, random_state=0).fit(X_train)
y3 = ensemble.predict(X_test)
assert_array_almost_equal(y1, y3)
