Example #1
0
def test_base_estimator():
    # Test different base estimators.
    from mrex.ensemble import RandomForestClassifier

    # XXX doesn't work with y_class because RF doesn't support classes_
    # Shouldn't AdaBoost run a LabelBinarizer?
    clf = AdaBoostClassifier(RandomForestClassifier())
    clf.fit(X, y_regr)

    clf = AdaBoostClassifier(SVC(), algorithm="SAMME")
    clf.fit(X, y_class)

    from mrex.ensemble import RandomForestRegressor

    clf = AdaBoostRegressor(RandomForestRegressor(), random_state=0)
    clf.fit(X, y_regr)

    clf = AdaBoostRegressor(SVR(), random_state=0)
    clf.fit(X, y_regr)

    # Check that an empty discrete ensemble fails in fit, not predict.
    X_fail = [[1, 1], [1, 1], [1, 1], [1, 1]]
    y_fail = ["foo", "bar", 1, 2]
    clf = AdaBoostClassifier(SVC(), algorithm="SAMME")
    assert_raises_regexp(ValueError, "worse than random", clf.fit, X_fail,
                         y_fail)
Example #2
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def test_number_of_subsets_of_features():
    # In RFE, 'number_of_subsets_of_features'
    # = the number of iterations in '_fit'
    # = max(ranking_)
    # = 1 + (n_features + step - n_features_to_select - 1) // step
    # After optimization #4534, this number
    # = 1 + np.ceil((n_features - n_features_to_select) / float(step))
    # This test case is to test their equivalence, refer to #4534 and #3824

    def formula1(n_features, n_features_to_select, step):
        return 1 + ((n_features + step - n_features_to_select - 1) // step)

    def formula2(n_features, n_features_to_select, step):
        return 1 + np.ceil((n_features - n_features_to_select) / float(step))

    # RFE
    # Case 1, n_features - n_features_to_select is divisible by step
    # Case 2, n_features - n_features_to_select is not divisible by step
    n_features_list = [11, 11]
    n_features_to_select_list = [3, 3]
    step_list = [2, 3]
    for n_features, n_features_to_select, step in zip(
            n_features_list, n_features_to_select_list, step_list):
        generator = check_random_state(43)
        X = generator.normal(size=(100, n_features))
        y = generator.rand(100).round()
        rfe = RFE(estimator=SVC(kernel="linear"),
                  n_features_to_select=n_features_to_select,
                  step=step)
        rfe.fit(X, y)
        # this number also equals to the maximum of ranking_
        assert (np.max(rfe.ranking_) == formula1(n_features,
                                                 n_features_to_select, step))
        assert (np.max(rfe.ranking_) == formula2(n_features,
                                                 n_features_to_select, step))

    # In RFECV, 'fit' calls 'RFE._fit'
    # 'number_of_subsets_of_features' of RFE
    # = the size of 'grid_scores' of RFECV
    # = the number of iterations of the for loop before optimization #4534

    # RFECV, n_features_to_select = 1
    # Case 1, n_features - 1 is divisible by step
    # Case 2, n_features - 1 is not divisible by step

    n_features_to_select = 1
    n_features_list = [11, 10]
    step_list = [2, 2]
    for n_features, step in zip(n_features_list, step_list):
        generator = check_random_state(43)
        X = generator.normal(size=(100, n_features))
        y = generator.rand(100).round()
        rfecv = RFECV(estimator=SVC(kernel="linear"), step=step)
        rfecv.fit(X, y)

        assert (rfecv.grid_scores_.shape[0] == formula1(
            n_features, n_features_to_select, step))
        assert (rfecv.grid_scores_.shape[0] == formula2(
            n_features, n_features_to_select, step))
Example #3
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def test_make_pipeline_memory():
    cachedir = mkdtemp()
    if LooseVersion(joblib.__version__) < LooseVersion('0.12'):
        # Deal with change of API in joblib
        memory = joblib.Memory(cachedir=cachedir, verbose=10)
    else:
        memory = joblib.Memory(location=cachedir, verbose=10)
    pipeline = make_pipeline(DummyTransf(), SVC(), memory=memory)
    assert pipeline.memory is memory
    pipeline = make_pipeline(DummyTransf(), SVC())
    assert pipeline.memory is None
    assert len(pipeline) == 2

    shutil.rmtree(cachedir)
Example #4
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def test_set_params():
    # test nested estimator parameter setting
    clf = Pipeline([("svc", SVC())])
    # non-existing parameter in svc
    assert_raises(ValueError, clf.set_params, svc__stupid_param=True)
    # non-existing parameter of pipeline
    assert_raises(ValueError, clf.set_params, svm__stupid_param=True)
Example #5
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def test_is_classifier():
    svc = SVC()
    assert is_classifier(svc)
    assert is_classifier(GridSearchCV(svc, {'C': [0.1, 1]}))
    assert is_classifier(Pipeline([('svc', svc)]))
    assert is_classifier(
        Pipeline([('svc_cv', GridSearchCV(svc, {'C': [0.1, 1]}))]))
Example #6
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def test_ovr_partial_fit():
    # Test if partial_fit is working as intended
    X, y = shuffle(iris.data, iris.target, random_state=0)
    ovr = OneVsRestClassifier(MultinomialNB())
    ovr.partial_fit(X[:100], y[:100], np.unique(y))
    ovr.partial_fit(X[100:], y[100:])
    pred = ovr.predict(X)
    ovr2 = OneVsRestClassifier(MultinomialNB())
    pred2 = ovr2.fit(X, y).predict(X)

    assert_almost_equal(pred, pred2)
    assert len(ovr.estimators_) == len(np.unique(y))
    assert np.mean(y == pred) > 0.65

    # Test when mini batches doesn't have all classes
    # with SGDClassifier
    X = np.abs(np.random.randn(14, 2))
    y = [1, 1, 1, 1, 2, 3, 3, 0, 0, 2, 3, 1, 2, 3]

    ovr = OneVsRestClassifier(
        SGDClassifier(max_iter=1, tol=None, shuffle=False, random_state=0))
    ovr.partial_fit(X[:7], y[:7], np.unique(y))
    ovr.partial_fit(X[7:], y[7:])
    pred = ovr.predict(X)
    ovr1 = OneVsRestClassifier(
        SGDClassifier(max_iter=1, tol=None, shuffle=False, random_state=0))
    pred1 = ovr1.fit(X, y).predict(X)
    assert np.mean(pred == y) == np.mean(pred1 == y)

    # test partial_fit only exists if estimator has it:
    ovr = OneVsRestClassifier(SVC())
    assert not hasattr(ovr, "partial_fit")
Example #7
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def test_pipeline_methods_preprocessing_svm():
    # Test the various methods of the pipeline (preprocessing + svm).
    iris = load_iris()
    X = iris.data
    y = iris.target
    n_samples = X.shape[0]
    n_classes = len(np.unique(y))
    scaler = StandardScaler()
    pca = PCA(n_components=2, svd_solver='randomized', whiten=True)
    clf = SVC(probability=True, random_state=0, decision_function_shape='ovr')

    for preprocessing in [scaler, pca]:
        pipe = Pipeline([('preprocess', preprocessing), ('svc', clf)])
        pipe.fit(X, y)

        # check shapes of various prediction functions
        predict = pipe.predict(X)
        assert predict.shape == (n_samples,)

        proba = pipe.predict_proba(X)
        assert proba.shape == (n_samples, n_classes)

        log_proba = pipe.predict_log_proba(X)
        assert log_proba.shape == (n_samples, n_classes)

        decision_function = pipe.decision_function(X)
        assert decision_function.shape == (n_samples, n_classes)

        pipe.score(X, y)
Example #8
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def test_rfe_estimator_tags():
    rfe = RFE(SVC(kernel='linear'))
    assert rfe._estimator_type == "classifier"
    # make sure that cross-validation is stratified
    iris = load_iris()
    score = cross_val_score(rfe, iris.data, iris.target)
    assert score.min() > .7
Example #9
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def test_rfe():
    generator = check_random_state(0)
    iris = load_iris()
    X = np.c_[iris.data, generator.normal(size=(len(iris.data), 6))]
    X_sparse = sparse.csr_matrix(X)
    y = iris.target

    # dense model
    clf = SVC(kernel="linear")
    rfe = RFE(estimator=clf, n_features_to_select=4, step=0.1)
    rfe.fit(X, y)
    X_r = rfe.transform(X)
    clf.fit(X_r, y)
    assert len(rfe.ranking_) == X.shape[1]

    # sparse model
    clf_sparse = SVC(kernel="linear")
    rfe_sparse = RFE(estimator=clf_sparse, n_features_to_select=4, step=0.1)
    rfe_sparse.fit(X_sparse, y)
    X_r_sparse = rfe_sparse.transform(X_sparse)

    assert X_r.shape == iris.data.shape
    assert_array_almost_equal(X_r[:10], iris.data[:10])

    assert_array_almost_equal(rfe.predict(X), clf.predict(iris.data))
    assert rfe.score(X, y) == clf.score(iris.data, iris.target)
    assert_array_almost_equal(X_r, X_r_sparse.toarray())
Example #10
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def test_check_estimator_pairwise():
    # check that check_estimator() works on estimator with _pairwise
    # kernel or  metric

    # test precomputed kernel
    est = SVC(kernel='precomputed')
    check_estimator(est)

    # test precomputed metric
    est = KNeighborsRegressor(metric='precomputed')
    check_estimator(est)
Example #11
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def test_safe_split_with_precomputed_kernel():
    clf = SVC()
    clfp = SVC(kernel="precomputed")

    iris = datasets.load_iris()
    X, y = iris.data, iris.target
    K = np.dot(X, X.T)

    cv = ShuffleSplit(test_size=0.25, random_state=0)
    train, test = list(cv.split(X))[0]

    X_train, y_train = _safe_split(clf, X, y, train)
    K_train, y_train2 = _safe_split(clfp, K, y, train)
    assert_array_almost_equal(K_train, np.dot(X_train, X_train.T))
    assert_array_almost_equal(y_train, y_train2)

    X_test, y_test = _safe_split(clf, X, y, test, train)
    K_test, y_test2 = _safe_split(clfp, K, y, test, train)
    assert_array_almost_equal(K_test, np.dot(X_test, X_train.T))
    assert_array_almost_equal(y_test, y_test2)
Example #12
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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
Example #13
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def test_pipeline_wrong_memory():
    # Test that an error is raised when memory is not a string or a Memory
    # instance
    iris = load_iris()
    X = iris.data
    y = iris.target
    # Define memory as an integer
    memory = 1
    cached_pipe = Pipeline([('transf', DummyTransf()),
                            ('svc', SVC())], memory=memory)
    assert_raises_regex(ValueError, "'memory' should be None, a string or"
                        " have the same interface as joblib.Memory."
                        " Got memory='1' instead.", cached_pipe.fit, X, y)
Example #14
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def plot_subfigure(X, Y, subplot, title, transform):
    if transform == "pca":
        X = PCA(n_components=2).fit_transform(X)
    elif transform == "cca":
        X = CCA(n_components=2).fit(X, Y).transform(X)
    else:
        raise ValueError

    min_x = np.min(X[:, 0])
    max_x = np.max(X[:, 0])

    min_y = np.min(X[:, 1])
    max_y = np.max(X[:, 1])

    classif = OneVsRestClassifier(SVC(kernel='linear'))
    classif.fit(X, Y)

    plt.subplot(2, 2, subplot)
    plt.title(title)

    zero_class = np.where(Y[:, 0])
    one_class = np.where(Y[:, 1])
    plt.scatter(X[:, 0], X[:, 1], s=40, c='gray', edgecolors=(0, 0, 0))
    plt.scatter(X[zero_class, 0],
                X[zero_class, 1],
                s=160,
                edgecolors='b',
                facecolors='none',
                linewidths=2,
                label='Class 1')
    plt.scatter(X[one_class, 0],
                X[one_class, 1],
                s=80,
                edgecolors='orange',
                facecolors='none',
                linewidths=2,
                label='Class 2')

    plot_hyperplane(classif.estimators_[0], min_x, max_x, 'k--',
                    'Boundary\nfor class 1')
    plot_hyperplane(classif.estimators_[1], min_x, max_x, 'k-.',
                    'Boundary\nfor class 2')
    plt.xticks(())
    plt.yticks(())

    plt.xlim(min_x - .5 * max_x, max_x + .5 * max_x)
    plt.ylim(min_y - .5 * max_y, max_y + .5 * max_y)
    if subplot == 2:
        plt.xlabel('First principal component')
        plt.ylabel('Second principal component')
        plt.legend(loc="upper left")
Example #15
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def test_pipeline_methods_pca_svm():
    # Test the various methods of the pipeline (pca + svm).
    iris = load_iris()
    X = iris.data
    y = iris.target
    # Test with PCA + SVC
    clf = SVC(probability=True, random_state=0)
    pca = PCA(svd_solver='full', n_components='mle', whiten=True)
    pipe = Pipeline([('pca', pca), ('svc', clf)])
    pipe.fit(X, y)
    pipe.predict(X)
    pipe.predict_proba(X)
    pipe.predict_log_proba(X)
    pipe.score(X, y)
Example #16
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def test_ovo_partial_fit_predict():
    temp = datasets.load_iris()
    X, y = temp.data, temp.target
    ovo1 = OneVsOneClassifier(MultinomialNB())
    ovo1.partial_fit(X[:100], y[:100], np.unique(y))
    ovo1.partial_fit(X[100:], y[100:])
    pred1 = ovo1.predict(X)

    ovo2 = OneVsOneClassifier(MultinomialNB())
    ovo2.fit(X, y)
    pred2 = ovo2.predict(X)
    assert len(ovo1.estimators_) == n_classes * (n_classes - 1) / 2
    assert np.mean(y == pred1) > 0.65
    assert_almost_equal(pred1, pred2)

    # Test when mini-batches have binary target classes
    ovo1 = OneVsOneClassifier(MultinomialNB())
    ovo1.partial_fit(X[:60], y[:60], np.unique(y))
    ovo1.partial_fit(X[60:], y[60:])
    pred1 = ovo1.predict(X)
    ovo2 = OneVsOneClassifier(MultinomialNB())
    pred2 = ovo2.fit(X, y).predict(X)

    assert_almost_equal(pred1, pred2)
    assert len(ovo1.estimators_) == len(np.unique(y))
    assert np.mean(y == pred1) > 0.65

    ovo = OneVsOneClassifier(MultinomialNB())
    X = np.random.rand(14, 2)
    y = [1, 1, 2, 3, 3, 0, 0, 4, 4, 4, 4, 4, 2, 2]
    ovo.partial_fit(X[:7], y[:7], [0, 1, 2, 3, 4])
    ovo.partial_fit(X[7:], y[7:])
    pred = ovo.predict(X)
    ovo2 = OneVsOneClassifier(MultinomialNB())
    pred2 = ovo2.fit(X, y).predict(X)
    assert_almost_equal(pred, pred2)

    # raises error when mini-batch does not have classes from all_classes
    ovo = OneVsOneClassifier(MultinomialNB())
    error_y = [0, 1, 2, 3, 4, 5, 2]
    message_re = escape("Mini-batch contains {0} while "
                        "it must be subset of {1}".format(
                            np.unique(error_y), np.unique(y)))
    assert_raises_regexp(ValueError, message_re, ovo.partial_fit, X[:7],
                         error_y, np.unique(y))

    # test partial_fit only exists if estimator has it:
    ovr = OneVsOneClassifier(SVC())
    assert not hasattr(ovr, "partial_fit")
Example #17
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def test_rfe_cv_n_jobs():
    generator = check_random_state(0)
    iris = load_iris()
    X = np.c_[iris.data, generator.normal(size=(len(iris.data), 6))]
    y = iris.target

    rfecv = RFECV(estimator=SVC(kernel='linear'))
    rfecv.fit(X, y)
    rfecv_ranking = rfecv.ranking_
    rfecv_grid_scores = rfecv.grid_scores_

    rfecv.set_params(n_jobs=2)
    rfecv.fit(X, y)
    assert_array_almost_equal(rfecv.ranking_, rfecv_ranking)
    assert_array_almost_equal(rfecv.grid_scores_, rfecv_grid_scores)
Example #18
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def test_rfecv_verbose_output():
    # Check verbose=1 is producing an output.
    from io import StringIO
    import sys
    sys.stdout = StringIO()

    generator = check_random_state(0)
    iris = load_iris()
    X = np.c_[iris.data, generator.normal(size=(len(iris.data), 6))]
    y = list(iris.target)

    rfecv = RFECV(estimator=SVC(kernel="linear"), step=1, verbose=1)
    rfecv.fit(X, y)

    verbose_output = sys.stdout
    verbose_output.seek(0)
    assert len(verbose_output.readline()) > 0
Example #19
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def test_ovr_coef_():
    for base_classifier in [
            SVC(kernel='linear', random_state=0),
            LinearSVC(random_state=0)
    ]:
        # SVC has sparse coef with sparse input data

        ovr = OneVsRestClassifier(base_classifier)
        for X in [iris.data, sp.csr_matrix(iris.data)]:
            # test with dense and sparse coef
            ovr.fit(X, iris.target)
            shape = ovr.coef_.shape
            assert shape[0] == n_classes
            assert shape[1] == iris.data.shape[1]
            # don't densify sparse coefficients
            assert (sp.issparse(ovr.estimators_[0].coef_) == sp.issparse(
                ovr.coef_))
Example #20
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def test_rfe_features_importance():
    generator = check_random_state(0)
    iris = load_iris()
    X = np.c_[iris.data, generator.normal(size=(len(iris.data), 6))]
    y = iris.target

    clf = RandomForestClassifier(n_estimators=20,
                                 random_state=generator,
                                 max_depth=2)
    rfe = RFE(estimator=clf, n_features_to_select=4, step=0.1)
    rfe.fit(X, y)
    assert len(rfe.ranking_) == X.shape[1]

    clf_svc = SVC(kernel="linear")
    rfe_svc = RFE(estimator=clf_svc, n_features_to_select=4, step=0.1)
    rfe_svc.fit(X, y)

    # Check if the supports are equal
    assert_array_equal(rfe.get_support(), rfe_svc.get_support())
Example #21
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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)
Example #22
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def test_ovr_binary():
    # Toy dataset where features correspond directly to labels.
    X = np.array([[0, 0, 5], [0, 5, 0], [3, 0, 0], [0, 0, 6], [6, 0, 0]])
    y = ["eggs", "spam", "spam", "eggs", "spam"]
    Y = np.array([[0, 1, 1, 0, 1]]).T

    classes = set("eggs spam".split())

    def conduct_test(base_clf, test_predict_proba=False):
        clf = OneVsRestClassifier(base_clf).fit(X, y)
        assert set(clf.classes_) == classes
        y_pred = clf.predict(np.array([[0, 0, 4]]))[0]
        assert_array_equal(y_pred, ["eggs"])
        if hasattr(base_clf, 'decision_function'):
            dec = clf.decision_function(X)
            assert dec.shape == (5, )

        if test_predict_proba:
            X_test = np.array([[0, 0, 4]])
            probabilities = clf.predict_proba(X_test)
            assert 2 == len(probabilities[0])
            assert (clf.classes_[np.argmax(probabilities,
                                           axis=1)] == clf.predict(X_test))

        # test input as label indicator matrix
        clf = OneVsRestClassifier(base_clf).fit(X, Y)
        y_pred = clf.predict([[3, 0, 0]])[0]
        assert y_pred == 1

    for base_clf in (LinearSVC(random_state=0), LinearRegression(), Ridge(),
                     ElasticNet()):
        conduct_test(base_clf)

    for base_clf in (MultinomialNB(), SVC(probability=True),
                     LogisticRegression()):
        conduct_test(base_clf, test_predict_proba=True)
Example #23
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from mrex import datasets
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))
Example #24
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    }),
    (make_pipeline(
        KBinsDiscretizer(encode='onehot'),
        LogisticRegression(random_state=0)), {
            'kbinsdiscretizer__n_bins': np.arange(2, 10),
            'logisticregression__C': np.logspace(-2, 7, 10),
        }),
    (make_pipeline(
        KBinsDiscretizer(encode='onehot'), LinearSVC(random_state=0)), {
            'kbinsdiscretizer__n_bins': np.arange(2, 10),
            'linearsvc__C': np.logspace(-2, 7, 10),
        }),
    (GradientBoostingClassifier(n_estimators=50, random_state=0), {
        'learning_rate': np.logspace(-4, 0, 10)
    }),
    (SVC(random_state=0), {
        'C': np.logspace(-2, 7, 10)
    }),
]

names = [get_name(e) for e, g in classifiers]

n_samples = 100
datasets = [
    make_moons(n_samples=n_samples, noise=0.2, random_state=0),
    make_circles(n_samples=n_samples, noise=0.2, factor=0.5, random_state=1),
    make_classification(n_samples=n_samples, n_features=2, n_redundant=0,
                        n_informative=2, random_state=2,
                        n_clusters_per_class=1)
]
Example #25
0
def test_pipeline_init():
    # Test the various init parameters of the pipeline.
    assert_raises(TypeError, Pipeline)
    # Check that we can't instantiate pipelines with objects without fit
    # method
    assert_raises_regex(TypeError,
                        'Last step of Pipeline should implement fit '
                        'or be the string \'passthrough\''
                        '.*NoFit.*',
                        Pipeline, [('clf', NoFit())])
    # Smoke test with only an estimator
    clf = NoTrans()
    pipe = Pipeline([('svc', clf)])
    assert (pipe.get_params(deep=True) ==
                 dict(svc__a=None, svc__b=None, svc=clf,
                      **pipe.get_params(deep=False)))

    # Check that params are set
    pipe.set_params(svc__a=0.1)
    assert clf.a == 0.1
    assert clf.b is None
    # Smoke test the repr:
    repr(pipe)

    # Test with two objects
    clf = SVC()
    filter1 = SelectKBest(f_classif)
    pipe = Pipeline([('anova', filter1), ('svc', clf)])

    # Check that estimators are not cloned on pipeline construction
    assert pipe.named_steps['anova'] is filter1
    assert pipe.named_steps['svc'] is clf

    # Check that we can't instantiate with non-transformers on the way
    # Note that NoTrans implements fit, but not transform
    assert_raises_regex(TypeError,
                        'All intermediate steps should be transformers'
                        '.*\\bNoTrans\\b.*',
                        Pipeline, [('t', NoTrans()), ('svc', clf)])

    # Check that params are set
    pipe.set_params(svc__C=0.1)
    assert clf.C == 0.1
    # Smoke test the repr:
    repr(pipe)

    # Check that params are not set when naming them wrong
    assert_raises(ValueError, pipe.set_params, anova__C=0.1)

    # Test clone
    pipe2 = assert_no_warnings(clone, pipe)
    assert not pipe.named_steps['svc'] is pipe2.named_steps['svc']

    # Check that apart from estimators, the parameters are the same
    params = pipe.get_params(deep=True)
    params2 = pipe2.get_params(deep=True)

    for x in pipe.get_params(deep=False):
        params.pop(x)

    for x in pipe2.get_params(deep=False):
        params2.pop(x)

    # Remove estimators that where copied
    params.pop('svc')
    params.pop('anova')
    params2.pop('svc')
    params2.pop('anova')
    assert params == params2
Example #26
0
def test_pipeline_memory():
    iris = load_iris()
    X = iris.data
    y = iris.target
    cachedir = mkdtemp()
    try:
        if LooseVersion(joblib.__version__) < LooseVersion('0.12'):
            # Deal with change of API in joblib
            memory = joblib.Memory(cachedir=cachedir, verbose=10)
        else:
            memory = joblib.Memory(location=cachedir, verbose=10)
        # Test with Transformer + SVC
        clf = SVC(probability=True, random_state=0)
        transf = DummyTransf()
        pipe = Pipeline([('transf', clone(transf)), ('svc', clf)])
        cached_pipe = Pipeline([('transf', transf), ('svc', clf)],
                               memory=memory)

        # Memoize the transformer at the first fit
        cached_pipe.fit(X, y)
        pipe.fit(X, y)
        # Get the time stamp of the transformer in the cached pipeline
        ts = cached_pipe.named_steps['transf'].timestamp_
        # Check that cached_pipe and pipe yield identical results
        assert_array_equal(pipe.predict(X), cached_pipe.predict(X))
        assert_array_equal(pipe.predict_proba(X), cached_pipe.predict_proba(X))
        assert_array_equal(pipe.predict_log_proba(X),
                           cached_pipe.predict_log_proba(X))
        assert_array_equal(pipe.score(X, y), cached_pipe.score(X, y))
        assert_array_equal(pipe.named_steps['transf'].means_,
                           cached_pipe.named_steps['transf'].means_)
        assert not hasattr(transf, 'means_')
        # Check that we are reading the cache while fitting
        # a second time
        cached_pipe.fit(X, y)
        # Check that cached_pipe and pipe yield identical results
        assert_array_equal(pipe.predict(X), cached_pipe.predict(X))
        assert_array_equal(pipe.predict_proba(X), cached_pipe.predict_proba(X))
        assert_array_equal(pipe.predict_log_proba(X),
                           cached_pipe.predict_log_proba(X))
        assert_array_equal(pipe.score(X, y), cached_pipe.score(X, y))
        assert_array_equal(pipe.named_steps['transf'].means_,
                           cached_pipe.named_steps['transf'].means_)
        assert ts == cached_pipe.named_steps['transf'].timestamp_
        # Create a new pipeline with cloned estimators
        # Check that even changing the name step does not affect the cache hit
        clf_2 = SVC(probability=True, random_state=0)
        transf_2 = DummyTransf()
        cached_pipe_2 = Pipeline([('transf_2', transf_2), ('svc', clf_2)],
                                 memory=memory)
        cached_pipe_2.fit(X, y)

        # Check that cached_pipe and pipe yield identical results
        assert_array_equal(pipe.predict(X), cached_pipe_2.predict(X))
        assert_array_equal(pipe.predict_proba(X),
                           cached_pipe_2.predict_proba(X))
        assert_array_equal(pipe.predict_log_proba(X),
                           cached_pipe_2.predict_log_proba(X))
        assert_array_equal(pipe.score(X, y), cached_pipe_2.score(X, y))
        assert_array_equal(pipe.named_steps['transf'].means_,
                           cached_pipe_2.named_steps['transf_2'].means_)
        assert ts == cached_pipe_2.named_steps['transf_2'].timestamp_
    finally:
        shutil.rmtree(cachedir)
Example #27
0
from mrex.svm import SVC
from mrex.model_selection import StratifiedKFold
from mrex.feature_selection import RFECV
from mrex.datasets import make_classification

# Build a classification task using 3 informative features
X, y = make_classification(n_samples=1000,
                           n_features=25,
                           n_informative=3,
                           n_redundant=2,
                           n_repeated=0,
                           n_classes=8,
                           n_clusters_per_class=1,
                           random_state=0)

# Create the RFE object and compute a cross-validated score.
svc = SVC(kernel="linear")
# The "accuracy" scoring is proportional to the number of correct
# classifications
rfecv = RFECV(estimator=svc, step=1, cv=StratifiedKFold(2), scoring='accuracy')
rfecv.fit(X, y)

print("Optimal number of features : %d" % rfecv.n_features_)

# Plot number of features VS. cross-validation scores
plt.figure()
plt.xlabel("Number of features selected")
plt.ylabel("Cross validation score (nb of correct classifications)")
plt.plot(range(1, len(rfecv.grid_scores_) + 1), rfecv.grid_scores_)
plt.show()
Example #28
0
X_train, X_test, y_train, y_test = train_test_split(
    X, y, test_size=0.5, random_state=0)

# Set the parameters by cross-validation
tuned_parameters = [{'kernel': ['rbf'], 'gamma': [1e-3, 1e-4],
                     'C': [1, 10, 100, 1000]},
                    {'kernel': ['linear'], 'C': [1, 10, 100, 1000]}]

scores = ['precision', 'recall']

for score in scores:
    print("# Tuning hyper-parameters for %s" % score)
    print()

    clf = GridSearchCV(
        SVC(), tuned_parameters, scoring='%s_macro' % score
    )
    clf.fit(X_train, y_train)

    print("Best parameters set found on development set:")
    print()
    print(clf.best_params_)
    print()
    print("Grid scores on development set:")
    print()
    means = clf.cv_results_['mean_test_score']
    stds = clf.cv_results_['std_test_score']
    for mean, std, params in zip(means, stds, clf.cv_results_['params']):
        print("%0.3f (+/-%0.03f) for %r"
              % (mean, std * 2, params))
    print()
Example #29
0
a digit classification task.

.. note::

    See also :ref:`sphx_glr_auto_examples_feature_selection_plot_rfe_with_cross_validation.py`

"""
print(__doc__)

from mrex.svm import SVC
from mrex.datasets import load_digits
from mrex.feature_selection import RFE
import matplotlib.pyplot as plt

# Load the digits dataset
digits = load_digits()
X = digits.images.reshape((len(digits.images), -1))
y = digits.target

# Create the RFE object and rank each pixel
svc = SVC(kernel="linear", C=1)
rfe = RFE(estimator=svc, n_features_to_select=1, step=1)
rfe.fit(X, y)
ranking = rfe.ranking_.reshape(digits.images[0].shape)

# Plot pixel ranking
plt.matshow(ranking, cmap=plt.cm.Blues)
plt.colorbar()
plt.title("Ranking of pixels with RFE")
plt.show()
Example #30
0
def test_rfecv():
    generator = check_random_state(0)
    iris = load_iris()
    X = np.c_[iris.data, generator.normal(size=(len(iris.data), 6))]
    y = list(iris.target)  # regression test: list should be supported

    # Test using the score function
    rfecv = RFECV(estimator=SVC(kernel="linear"), step=1)
    rfecv.fit(X, y)
    # non-regression test for missing worst feature:
    assert len(rfecv.grid_scores_) == X.shape[1]
    assert len(rfecv.ranking_) == X.shape[1]
    X_r = rfecv.transform(X)

    # All the noisy variable were filtered out
    assert_array_equal(X_r, iris.data)

    # same in sparse
    rfecv_sparse = RFECV(estimator=SVC(kernel="linear"), step=1)
    X_sparse = sparse.csr_matrix(X)
    rfecv_sparse.fit(X_sparse, y)
    X_r_sparse = rfecv_sparse.transform(X_sparse)
    assert_array_equal(X_r_sparse.toarray(), iris.data)

    # Test using a customized loss function
    scoring = make_scorer(zero_one_loss, greater_is_better=False)
    rfecv = RFECV(estimator=SVC(kernel="linear"), step=1, scoring=scoring)
    ignore_warnings(rfecv.fit)(X, y)
    X_r = rfecv.transform(X)
    assert_array_equal(X_r, iris.data)

    # Test using a scorer
    scorer = get_scorer('accuracy')
    rfecv = RFECV(estimator=SVC(kernel="linear"), step=1, scoring=scorer)
    rfecv.fit(X, y)
    X_r = rfecv.transform(X)
    assert_array_equal(X_r, iris.data)

    # Test fix on grid_scores
    def test_scorer(estimator, X, y):
        return 1.0

    rfecv = RFECV(estimator=SVC(kernel="linear"), step=1, scoring=test_scorer)
    rfecv.fit(X, y)
    assert_array_equal(rfecv.grid_scores_, np.ones(len(rfecv.grid_scores_)))
    # In the event of cross validation score ties, the expected behavior of
    # RFECV is to return the FEWEST features that maximize the CV score.
    # Because test_scorer always returns 1.0 in this example, RFECV should
    # reduce the dimensionality to a single feature (i.e. n_features_ = 1)
    assert rfecv.n_features_ == 1

    # Same as the first two tests, but with step=2
    rfecv = RFECV(estimator=SVC(kernel="linear"), step=2)
    rfecv.fit(X, y)
    assert len(rfecv.grid_scores_) == 6
    assert len(rfecv.ranking_) == X.shape[1]
    X_r = rfecv.transform(X)
    assert_array_equal(X_r, iris.data)

    rfecv_sparse = RFECV(estimator=SVC(kernel="linear"), step=2)
    X_sparse = sparse.csr_matrix(X)
    rfecv_sparse.fit(X_sparse, y)
    X_r_sparse = rfecv_sparse.transform(X_sparse)
    assert_array_equal(X_r_sparse.toarray(), iris.data)

    # Verifying that steps < 1 don't blow up.
    rfecv_sparse = RFECV(estimator=SVC(kernel="linear"), step=.2)
    X_sparse = sparse.csr_matrix(X)
    rfecv_sparse.fit(X_sparse, y)
    X_r_sparse = rfecv_sparse.transform(X_sparse)
    assert_array_equal(X_r_sparse.toarray(), iris.data)