def test_tie_situation():
"""Check voting classifier selects smaller class label in tie situation."""
clf1 = LogisticRegression(random_state=123, solver='liblinear')
clf2 = RandomForestClassifier(random_state=123)
eclf = VotingClassifier(estimators=[('lr', clf1), ('rf', clf2)],
voting='hard')
assert clf1.fit(X, y).predict(X)[73] == 2
assert clf2.fit(X, y).predict(X)[73] == 1
assert eclf.fit(X, y).predict(X)[73] == 1
def test_predictproba_hardvoting():
eclf = VotingClassifier(estimators=[('lr1', LogisticRegression()),
('lr2', LogisticRegression())],
voting='hard')
msg = "predict_proba is not available when voting='hard'"
with pytest.raises(AttributeError, match=msg):
eclf.predict_proba
assert not hasattr(eclf, "predict_proba")
eclf.fit(X, y)
assert not hasattr(eclf, "predict_proba")
def test_sample_weight_kwargs():
"""Check that VotingClassifier passes sample_weight as kwargs"""
class MockClassifier(BaseEstimator, ClassifierMixin):
"""Mock Classifier to check that sample_weight is received as kwargs"""
def fit(self, X, y, *args, **sample_weight):
assert 'sample_weight' in sample_weight
clf = MockClassifier()
eclf = VotingClassifier(estimators=[('mock', clf)], voting='soft')
# Should not raise an error.
eclf.fit(X, y, sample_weight=np.ones((len(y),)))
def test_multilabel():
"""Check if error is raised for multilabel classification."""
X, y = make_multilabel_classification(n_classes=2, n_labels=1,
allow_unlabeled=False,
random_state=123)
clf = OneVsRestClassifier(SVC(kernel='linear'))
eclf = VotingClassifier(estimators=[('ovr', clf)], voting='hard')
try:
eclf.fit(X, y)
except NotImplementedError:
return
def test_estimator_weights_format():
# Test estimator weights inputs as list and array
clf1 = LogisticRegression(random_state=123)
clf2 = RandomForestClassifier(random_state=123)
eclf1 = VotingClassifier(estimators=[
('lr', clf1), ('rf', clf2)],
weights=[1, 2],
voting='soft')
eclf2 = VotingClassifier(estimators=[
('lr', clf1), ('rf', clf2)],
weights=np.array((1, 2)),
voting='soft')
eclf1.fit(X, y)
eclf2.fit(X, y)
assert_array_almost_equal(eclf1.predict_proba(X), eclf2.predict_proba(X))
def test_majority_label_iris():
"""Check classification by majority label on dataset iris."""
clf1 = LogisticRegression(solver='liblinear', random_state=123)
clf2 = RandomForestClassifier(n_estimators=10, random_state=123)
clf3 = GaussianNB()
eclf = VotingClassifier(estimators=[
('lr', clf1), ('rf', clf2), ('gnb', clf3)],
voting='hard')
scores = cross_val_score(eclf, X, y, scoring='accuracy')
assert_almost_equal(scores.mean(), 0.95, decimal=2)
def test_weights_iris():
"""Check classification by average probabilities on dataset iris."""
clf1 = LogisticRegression(random_state=123)
clf2 = RandomForestClassifier(random_state=123)
clf3 = GaussianNB()
eclf = VotingClassifier(estimators=[
('lr', clf1), ('rf', clf2), ('gnb', clf3)],
voting='soft',
weights=[1, 2, 10])
scores = cross_val_score(eclf, X, y, scoring='accuracy')
assert_almost_equal(scores.mean(), 0.93, decimal=2)
def test_estimator_init():
eclf = VotingClassifier(estimators=[])
msg = ('Invalid `estimators` attribute, `estimators` should be'
' a list of (string, estimator) tuples')
assert_raise_message(AttributeError, msg, eclf.fit, X, y)
clf = LogisticRegression(random_state=1)
eclf = VotingClassifier(estimators=[('lr', clf)], voting='error')
msg = ('Voting must be \'soft\' or \'hard\'; got (voting=\'error\')')
assert_raise_message(ValueError, msg, eclf.fit, X, y)
eclf = VotingClassifier(estimators=[('lr', clf)], weights=[1, 2])
msg = ('Number of `estimators` and weights must be equal'
'; got 2 weights, 1 estimators')
assert_raise_message(ValueError, msg, eclf.fit, X, y)
eclf = VotingClassifier(estimators=[('lr', clf), ('lr', clf)],
weights=[1, 2])
msg = "Names provided are not unique: ['lr', 'lr']"
assert_raise_message(ValueError, msg, eclf.fit, X, y)
eclf = VotingClassifier(estimators=[('lr__', clf)])
msg = "Estimator names must not contain __: got ['lr__']"
assert_raise_message(ValueError, msg, eclf.fit, X, y)
eclf = VotingClassifier(estimators=[('estimators', clf)])
msg = "Estimator names conflict with constructor arguments: ['estimators']"
assert_raise_message(ValueError, msg, eclf.fit, X, y)
def test_predict_on_toy_problem():
"""Manually check predicted class labels for toy dataset."""
clf1 = LogisticRegression(random_state=123)
clf2 = RandomForestClassifier(random_state=123)
clf3 = GaussianNB()
X = np.array([[-1.1, -1.5],
[-1.2, -1.4],
[-3.4, -2.2],
[1.1, 1.2],
[2.1, 1.4],
[3.1, 2.3]])
y = np.array([1, 1, 1, 2, 2, 2])
assert all(clf1.fit(X, y).predict(X)) == all([1, 1, 1, 2, 2, 2])
assert all(clf2.fit(X, y).predict(X)) == all([1, 1, 1, 2, 2, 2])
assert all(clf3.fit(X, y).predict(X)) == all([1, 1, 1, 2, 2, 2])
eclf = VotingClassifier(estimators=[
('lr', clf1), ('rf', clf2), ('gnb', clf3)],
voting='hard',
weights=[1, 1, 1])
assert all(eclf.fit(X, y).predict(X)) == all([1, 1, 1, 2, 2, 2])
eclf = VotingClassifier(estimators=[
('lr', clf1), ('rf', clf2), ('gnb', clf3)],
voting='soft',
weights=[1, 1, 1])
assert all(eclf.fit(X, y).predict(X)) == all([1, 1, 1, 2, 2, 2])
def test_gridsearch():
"""Check GridSearch support."""
clf1 = LogisticRegression(random_state=1)
clf2 = RandomForestClassifier(random_state=1)
clf3 = GaussianNB()
eclf = VotingClassifier(estimators=[
('lr', clf1), ('rf', clf2), ('gnb', clf3)],
voting='soft')
params = {'lr__C': [1.0, 100.0],
'voting': ['soft', 'hard'],
'weights': [[0.5, 0.5, 0.5], [1.0, 0.5, 0.5]]}
grid = GridSearchCV(estimator=eclf, param_grid=params)
grid.fit(iris.data, iris.target)
def test_notfitted():
eclf = VotingClassifier(estimators=[('lr1', LogisticRegression()),
('lr2', LogisticRegression())],
voting='soft')
ereg = VotingRegressor([('dr', DummyRegressor())])
msg = ("This %s instance is not fitted yet. Call \'fit\'"
" with appropriate arguments before using this method.")
assert_raise_message(NotFittedError, msg % 'VotingClassifier',
eclf.predict, X)
assert_raise_message(NotFittedError, msg % 'VotingClassifier',
eclf.predict_proba, X)
assert_raise_message(NotFittedError, msg % 'VotingClassifier',
eclf.transform, X)
assert_raise_message(NotFittedError, msg % 'VotingRegressor',
ereg.predict, X_r)
assert_raise_message(NotFittedError, msg % 'VotingRegressor',
ereg.transform, X_r)
def test_parallel_fit():
"""Check parallel backend of VotingClassifier on toy dataset."""
clf1 = LogisticRegression(random_state=123)
clf2 = RandomForestClassifier(random_state=123)
clf3 = GaussianNB()
X = np.array([[-1.1, -1.5], [-1.2, -1.4], [-3.4, -2.2], [1.1, 1.2]])
y = np.array([1, 1, 2, 2])
eclf1 = VotingClassifier(estimators=[
('lr', clf1), ('rf', clf2), ('gnb', clf3)],
voting='soft',
n_jobs=1).fit(X, y)
eclf2 = VotingClassifier(estimators=[
('lr', clf1), ('rf', clf2), ('gnb', clf3)],
voting='soft',
n_jobs=2).fit(X, y)
assert_array_equal(eclf1.predict(X), eclf2.predict(X))
assert_array_almost_equal(eclf1.predict_proba(X), eclf2.predict_proba(X))
def test_predict_proba_on_toy_problem():
"""Calculate predicted probabilities on toy dataset."""
clf1 = LogisticRegression(random_state=123)
clf2 = RandomForestClassifier(random_state=123)
clf3 = GaussianNB()
X = np.array([[-1.1, -1.5], [-1.2, -1.4], [-3.4, -2.2], [1.1, 1.2]])
y = np.array([1, 1, 2, 2])
clf1_res = np.array([[0.59790391, 0.40209609],
[0.57622162, 0.42377838],
[0.50728456, 0.49271544],
[0.40241774, 0.59758226]])
clf2_res = np.array([[0.8, 0.2],
[0.8, 0.2],
[0.2, 0.8],
[0.3, 0.7]])
clf3_res = np.array([[0.9985082, 0.0014918],
[0.99845843, 0.00154157],
[0., 1.],
[0., 1.]])
t00 = (2*clf1_res[0][0] + clf2_res[0][0] + clf3_res[0][0]) / 4
t11 = (2*clf1_res[1][1] + clf2_res[1][1] + clf3_res[1][1]) / 4
t21 = (2*clf1_res[2][1] + clf2_res[2][1] + clf3_res[2][1]) / 4
t31 = (2*clf1_res[3][1] + clf2_res[3][1] + clf3_res[3][1]) / 4
eclf = VotingClassifier(estimators=[
('lr', clf1), ('rf', clf2), ('gnb', clf3)],
voting='soft',
weights=[2, 1, 1])
eclf_res = eclf.fit(X, y).predict_proba(X)
assert_almost_equal(t00, eclf_res[0][0], decimal=1)
assert_almost_equal(t11, eclf_res[1][1], decimal=1)
assert_almost_equal(t21, eclf_res[2][1], decimal=1)
assert_almost_equal(t31, eclf_res[3][1], decimal=1)
with pytest.raises(
AttributeError,
match="predict_proba is not available when voting='hard'"):
eclf = VotingClassifier(estimators=[
('lr', clf1), ('rf', clf2), ('gnb', clf3)],
voting='hard')
eclf.fit(X, y).predict_proba(X)
def test_sample_weight():
"""Tests sample_weight parameter of VotingClassifier"""
clf1 = LogisticRegression(random_state=123)
clf2 = RandomForestClassifier(random_state=123)
clf3 = SVC(probability=True, random_state=123)
eclf1 = VotingClassifier(estimators=[
('lr', clf1), ('rf', clf2), ('svc', clf3)],
voting='soft').fit(X, y, sample_weight=np.ones((len(y),)))
eclf2 = VotingClassifier(estimators=[
('lr', clf1), ('rf', clf2), ('svc', clf3)],
voting='soft').fit(X, y)
assert_array_equal(eclf1.predict(X), eclf2.predict(X))
assert_array_almost_equal(eclf1.predict_proba(X), eclf2.predict_proba(X))
sample_weight = np.random.RandomState(123).uniform(size=(len(y),))
eclf3 = VotingClassifier(estimators=[('lr', clf1)], voting='soft')
eclf3.fit(X, y, sample_weight)
clf1.fit(X, y, sample_weight)
assert_array_equal(eclf3.predict(X), clf1.predict(X))
assert_array_almost_equal(eclf3.predict_proba(X), clf1.predict_proba(X))
# check that an error is raised and indicative if sample_weight is not
# supported.
clf4 = KNeighborsClassifier()
eclf3 = VotingClassifier(estimators=[
('lr', clf1), ('svc', clf3), ('knn', clf4)],
voting='soft')
msg = ('Underlying estimator KNeighborsClassifier does not support '
'sample weights.')
with pytest.raises(ValueError, match=msg):
eclf3.fit(X, y, sample_weight)
# check that _parallel_fit_estimator will raise the right error
# it should raise the original error if this is not linked to sample_weight
class ClassifierErrorFit(BaseEstimator, ClassifierMixin):
def fit(self, X, y, sample_weight):
raise TypeError('Error unrelated to sample_weight.')
clf = ClassifierErrorFit()
with pytest.raises(TypeError, match='Error unrelated to sample_weight'):
clf.fit(X, y, sample_weight=sample_weight)
def test_transform():
"""Check transform method of VotingClassifier on toy dataset."""
clf1 = LogisticRegression(random_state=123)
clf2 = RandomForestClassifier(random_state=123)
clf3 = GaussianNB()
X = np.array([[-1.1, -1.5], [-1.2, -1.4], [-3.4, -2.2], [1.1, 1.2]])
y = np.array([1, 1, 2, 2])
eclf1 = VotingClassifier(estimators=[
('lr', clf1), ('rf', clf2), ('gnb', clf3)],
voting='soft').fit(X, y)
eclf2 = VotingClassifier(estimators=[
('lr', clf1), ('rf', clf2), ('gnb', clf3)],
voting='soft',
flatten_transform=True).fit(X, y)
eclf3 = VotingClassifier(estimators=[
('lr', clf1), ('rf', clf2), ('gnb', clf3)],
voting='soft',
flatten_transform=False).fit(X, y)
assert_array_equal(eclf1.transform(X).shape, (4, 6))
assert_array_equal(eclf2.transform(X).shape, (4, 6))
assert_array_equal(eclf3.transform(X).shape, (3, 4, 2))
assert_array_almost_equal(eclf1.transform(X),
eclf2.transform(X))
assert_array_almost_equal(
eclf3.transform(X).swapaxes(0, 1).reshape((4, 6)),
eclf2.transform(X)
)
def test_set_estimator_none(drop):
"""VotingClassifier set_params should be able to set estimators as None or
drop"""
# Test predict
clf1 = LogisticRegression(random_state=123)
clf2 = RandomForestClassifier(n_estimators=10, random_state=123)
clf3 = GaussianNB()
eclf1 = VotingClassifier(estimators=[('lr', clf1), ('rf', clf2),
('nb', clf3)],
voting='hard', weights=[1, 0, 0.5]).fit(X, y)
eclf2 = VotingClassifier(estimators=[('lr', clf1), ('rf', clf2),
('nb', clf3)],
voting='hard', weights=[1, 1, 0.5])
eclf2.set_params(rf=drop).fit(X, y)
assert_array_equal(eclf1.predict(X), eclf2.predict(X))
assert dict(eclf2.estimators)["rf"] is drop
assert len(eclf2.estimators_) == 2
assert all(isinstance(est, (LogisticRegression, GaussianNB))
for est in eclf2.estimators_)
assert eclf2.get_params()["rf"] is drop
eclf1.set_params(voting='soft').fit(X, y)
eclf2.set_params(voting='soft').fit(X, y)
assert_array_equal(eclf1.predict(X), eclf2.predict(X))
assert_array_almost_equal(eclf1.predict_proba(X), eclf2.predict_proba(X))
msg = 'All estimators are None or "drop". At least one is required!'
assert_raise_message(
ValueError, msg, eclf2.set_params(lr=drop, rf=drop, nb=drop).fit, X, y)
# Test soft voting transform
X1 = np.array([[1], [2]])
y1 = np.array([1, 2])
eclf1 = VotingClassifier(estimators=[('rf', clf2), ('nb', clf3)],
voting='soft', weights=[0, 0.5],
flatten_transform=False).fit(X1, y1)
eclf2 = VotingClassifier(estimators=[('rf', clf2), ('nb', clf3)],
voting='soft', weights=[1, 0.5],
flatten_transform=False)
eclf2.set_params(rf=drop).fit(X1, y1)
assert_array_almost_equal(eclf1.transform(X1),
np.array([[[0.7, 0.3], [0.3, 0.7]],
[[1., 0.], [0., 1.]]]))
assert_array_almost_equal(eclf2.transform(X1),
np.array([[[1., 0.],
[0., 1.]]]))
eclf1.set_params(voting='hard')
eclf2.set_params(voting='hard')
assert_array_equal(eclf1.transform(X1), np.array([[0, 0], [1, 1]]))
assert_array_equal(eclf2.transform(X1), np.array([[0], [1]]))
assert_array_equal(eclf1.transform(X).shape, (4, 6))
assert_array_equal(eclf2.transform(X).shape, (4, 6))
assert_array_equal(eclf3.transform(X).shape, (3, 4, 2))
assert_array_almost_equal(eclf1.transform(X),
eclf2.transform(X))
assert_array_almost_equal(
eclf3.transform(X).swapaxes(0, 1).reshape((4, 6)),
eclf2.transform(X)
)
@pytest.mark.parametrize(
"X, y, voter",
[(X, y, VotingClassifier(
[('lr', LogisticRegression()),
('rf', RandomForestClassifier(n_estimators=5))])),
(X_r, y_r, VotingRegressor(
[('lr', LinearRegression()),
('rf', RandomForestRegressor(n_estimators=5))]))]
)
@pytest.mark.parametrize("drop", [None, 'drop'])
def test_none_estimator_with_weights(X, y, voter, drop):
# check that an estimator can be set to None and passing some weight
# regression test for
# https://github.com/scikit-learn/scikit-learn/issues/13777
voter.fit(X, y, sample_weight=np.ones(y.shape))
voter.set_params(lr=drop)
voter.fit(X, y, sample_weight=np.ones(y.shape))
y_pred = voter.predict(X)
assert y_pred.shape == y.shape
def test_set_params():
"""set_params should be able to set estimators"""
clf1 = LogisticRegression(random_state=123, C=1.0)
clf2 = RandomForestClassifier(random_state=123, max_depth=None)
clf3 = GaussianNB()
eclf1 = VotingClassifier([('lr', clf1), ('rf', clf2)], voting='soft',
weights=[1, 2])
assert 'lr' in eclf1.named_estimators
assert eclf1.named_estimators.lr is eclf1.estimators[0][1]
assert eclf1.named_estimators.lr is eclf1.named_estimators['lr']
eclf1.fit(X, y)
assert 'lr' in eclf1.named_estimators_
assert eclf1.named_estimators_.lr is eclf1.estimators_[0]
assert eclf1.named_estimators_.lr is eclf1.named_estimators_['lr']
eclf2 = VotingClassifier([('lr', clf1), ('nb', clf3)], voting='soft',
weights=[1, 2])
eclf2.set_params(nb=clf2).fit(X, y)
assert not hasattr(eclf2, 'nb')
assert_array_equal(eclf1.predict(X), eclf2.predict(X))
assert_array_almost_equal(eclf1.predict_proba(X), eclf2.predict_proba(X))
assert eclf2.estimators[0][1].get_params() == clf1.get_params()
assert eclf2.estimators[1][1].get_params() == clf2.get_params()
eclf1.set_params(lr__C=10.0)
eclf2.set_params(nb__max_depth=5)
assert eclf1.estimators[0][1].get_params()['C'] == 10.0
assert eclf2.estimators[1][1].get_params()['max_depth'] == 5
assert (eclf1.get_params()["lr__C"] ==
eclf1.get_params()["lr"].get_params()['C'])
from mrex.tree import DecisionTreeClassifier
from mrex.neighbors import KNeighborsClassifier
from mrex.svm import SVC
from mrex.ensemble import VotingClassifier
# Loading some example data
iris = datasets.load_iris()
X = iris.data[:, [0, 2]]
y = iris.target
# Training classifiers
clf1 = DecisionTreeClassifier(max_depth=4)
clf2 = KNeighborsClassifier(n_neighbors=7)
clf3 = SVC(gamma=.1, kernel='rbf', probability=True)
eclf = VotingClassifier(estimators=[('dt', clf1), ('knn', clf2),
('svc', clf3)],
voting='soft',
weights=[2, 1, 2])
clf1.fit(X, y)
clf2.fit(X, y)
clf3.fit(X, y)
eclf.fit(X, y)
# Plotting decision regions
x_min, x_max = X[:, 0].min() - 1, X[:, 0].max() + 1
y_min, y_max = X[:, 1].min() - 1, X[:, 1].max() + 1
xx, yy = np.meshgrid(np.arange(x_min, x_max, 0.1),
np.arange(y_min, y_max, 0.1))
f, axarr = plt.subplots(2, 2, sharex='col', sharey='row', figsize=(10, 8))
import numpy as np
import matplotlib.pyplot as plt
from mrex.linear_model import LogisticRegression
from mrex.naive_bayes import GaussianNB
from mrex.ensemble import RandomForestClassifier
from mrex.ensemble import VotingClassifier
clf1 = LogisticRegression(max_iter=1000, random_state=123)
clf2 = RandomForestClassifier(n_estimators=100, random_state=123)
clf3 = GaussianNB()
X = np.array([[-1.0, -1.0], [-1.2, -1.4], [-3.4, -2.2], [1.1, 1.2]])
y = np.array([1, 1, 2, 2])
eclf = VotingClassifier(estimators=[('lr', clf1), ('rf', clf2), ('gnb', clf3)],
voting='soft',
weights=[1, 1, 5])
# predict class probabilities for all classifiers
probas = [c.fit(X, y).predict_proba(X) for c in (clf1, clf2, clf3, eclf)]
# get class probabilities for the first sample in the dataset
class1_1 = [pr[0, 0] for pr in probas]
class2_1 = [pr[0, 1] for pr in probas]
# plotting
N = 4 # number of groups
ind = np.arange(N) # group positions
width = 0.35 # bar width
