コード例 #1
0
def test_search_light():
    """Test SlidingEstimator."""
    from sklearn.linear_model import Ridge, LogisticRegression
    from sklearn.pipeline import make_pipeline
    from sklearn.metrics import roc_auc_score, make_scorer
    from sklearn.ensemble import BaggingClassifier
    from sklearn.base import is_classifier

    X, y = make_data()
    n_epochs, _, n_time = X.shape
    # init
    pytest.raises(ValueError, SlidingEstimator, 'foo')
    sl = SlidingEstimator(Ridge())
    assert (not is_classifier(sl))
    sl = SlidingEstimator(LogisticRegression())
    assert (is_classifier(sl))
    # fit
    assert_equal(sl.__repr__()[:18], '<SlidingEstimator(')
    sl.fit(X, y)
    assert_equal(sl.__repr__()[-28:], ', fitted with 10 estimators>')
    pytest.raises(ValueError, sl.fit, X[1:], y)
    pytest.raises(ValueError, sl.fit, X[:, :, 0], y)
    sl.fit(X, y, sample_weight=np.ones_like(y))

    # transforms
    pytest.raises(ValueError, sl.predict, X[:, :, :2])
    y_pred = sl.predict(X)
    assert (y_pred.dtype == int)
    assert_array_equal(y_pred.shape, [n_epochs, n_time])
    y_proba = sl.predict_proba(X)
    assert (y_proba.dtype == float)
    assert_array_equal(y_proba.shape, [n_epochs, n_time, 2])

    # score
    score = sl.score(X, y)
    assert_array_equal(score.shape, [n_time])
    assert (np.sum(np.abs(score)) != 0)
    assert (score.dtype == float)

    sl = SlidingEstimator(LogisticRegression())
    assert_equal(sl.scoring, None)

    # Scoring method
    for scoring in ['foo', 999]:
        sl = SlidingEstimator(LogisticRegression(), scoring=scoring)
        sl.fit(X, y)
        pytest.raises((ValueError, TypeError), sl.score, X, y)

    # Check sklearn's roc_auc fix: scikit-learn/scikit-learn#6874
    # -- 3 class problem
    sl = SlidingEstimator(LogisticRegression(random_state=0),
                          scoring='roc_auc')
    y = np.arange(len(X)) % 3
    sl.fit(X, y)
    pytest.raises(ValueError, sl.score, X, y)
    # -- 2 class problem not in [0, 1]
    y = np.arange(len(X)) % 2 + 1
    sl.fit(X, y)
    score = sl.score(X, y)
    assert_array_equal(score, [
        roc_auc_score(y - 1, _y_pred - 1)
        for _y_pred in sl.decision_function(X).T
    ])
    y = np.arange(len(X)) % 2

    # Cannot pass a metric as a scoring parameter
    sl1 = SlidingEstimator(LogisticRegression(), scoring=roc_auc_score)
    sl1.fit(X, y)
    pytest.raises(ValueError, sl1.score, X, y)

    # Now use string as scoring
    sl1 = SlidingEstimator(LogisticRegression(), scoring='roc_auc')
    sl1.fit(X, y)
    rng = np.random.RandomState(0)
    X = rng.randn(*X.shape)  # randomize X to avoid AUCs in [0, 1]
    score_sl = sl1.score(X, y)
    assert_array_equal(score_sl.shape, [n_time])
    assert (score_sl.dtype == float)

    # Check that scoring was applied adequately
    scoring = make_scorer(roc_auc_score, needs_threshold=True)
    score_manual = [
        scoring(est, x, y)
        for est, x in zip(sl1.estimators_, X.transpose(2, 0, 1))
    ]
    assert_array_equal(score_manual, score_sl)

    # n_jobs
    sl = SlidingEstimator(LogisticRegression(random_state=0),
                          n_jobs=1,
                          scoring='roc_auc')
    score_1job = sl.fit(X, y).score(X, y)
    sl.n_jobs = 2
    score_njobs = sl.fit(X, y).score(X, y)
    assert_array_equal(score_1job, score_njobs)
    sl.predict(X)

    # n_jobs > n_estimators
    sl.fit(X[..., [0]], y)
    sl.predict(X[..., [0]])

    # pipeline

    class _LogRegTransformer(LogisticRegression):
        # XXX needs transformer in pipeline to get first proba only
        def transform(self, X):
            return super(_LogRegTransformer, self).predict_proba(X)[..., 1]

    pipe = make_pipeline(SlidingEstimator(_LogRegTransformer()),
                         LogisticRegression())
    pipe.fit(X, y)
    pipe.predict(X)

    # n-dimensional feature space
    X = np.random.rand(10, 3, 4, 2)
    y = np.arange(10) % 2
    y_preds = list()
    for n_jobs in [1, 2]:
        pipe = SlidingEstimator(make_pipeline(Vectorizer(),
                                              LogisticRegression()),
                                n_jobs=n_jobs)
        y_preds.append(pipe.fit(X, y).predict(X))
        features_shape = pipe.estimators_[0].steps[0][1].features_shape_
        assert_array_equal(features_shape, [3, 4])
    assert_array_equal(y_preds[0], y_preds[1])

    # Bagging classifiers
    X = np.random.rand(10, 3, 4)
    for n_jobs in (1, 2):
        pipe = SlidingEstimator(BaggingClassifier(None, 2), n_jobs=n_jobs)
        pipe.fit(X, y)
        pipe.score(X, y)
        assert (isinstance(pipe.estimators_[0], BaggingClassifier))
コード例 #2
0
def test_cross_val_multiscore():
    """Test cross_val_multiscore for computing scores on decoding over time."""
    from sklearn.model_selection import KFold, StratifiedKFold, cross_val_score
    from sklearn.linear_model import LogisticRegression, LinearRegression

    if check_version('sklearn', '0.20'):
        logreg = LogisticRegression(solver='liblinear', random_state=0)
    else:
        logreg = LogisticRegression(random_state=0)

    # compare to cross-val-score
    X = np.random.rand(20, 3)
    y = np.arange(20) % 2
    cv = KFold(2, random_state=0, shuffle=True)
    clf = logreg
    assert_array_equal(cross_val_score(clf, X, y, cv=cv),
                       cross_val_multiscore(clf, X, y, cv=cv))

    # Test with search light
    X = np.random.rand(20, 4, 3)
    y = np.arange(20) % 2
    clf = SlidingEstimator(logreg, scoring='accuracy')
    scores_acc = cross_val_multiscore(clf, X, y, cv=cv)
    assert_array_equal(np.shape(scores_acc), [2, 3])

    # check values
    scores_acc_manual = list()
    for train, test in cv.split(X, y):
        clf.fit(X[train], y[train])
        scores_acc_manual.append(clf.score(X[test], y[test]))
    assert_array_equal(scores_acc, scores_acc_manual)

    # check scoring metric
    # raise an error if scoring is defined at cross-val-score level and
    # search light, because search light does not return a 1-dimensional
    # prediction.
    pytest.raises(ValueError,
                  cross_val_multiscore,
                  clf,
                  X,
                  y,
                  cv=cv,
                  scoring='roc_auc')
    clf = SlidingEstimator(logreg, scoring='roc_auc')
    scores_auc = cross_val_multiscore(clf, X, y, cv=cv, n_jobs=1)
    scores_auc_manual = list()
    for train, test in cv.split(X, y):
        clf.fit(X[train], y[train])
        scores_auc_manual.append(clf.score(X[test], y[test]))
    assert_array_equal(scores_auc, scores_auc_manual)

    # indirectly test that cross_val_multiscore rightly detects the type of
    # estimator and generates a StratifiedKFold for classiers and a KFold
    # otherwise
    X = np.random.randn(1000, 3)
    y = np.ones(1000, dtype=int)
    y[::2] = 0
    clf = logreg
    reg = LinearRegression()
    for cross_val in (cross_val_score, cross_val_multiscore):
        manual = cross_val(clf, X, y, cv=StratifiedKFold(2))
        auto = cross_val(clf, X, y, cv=2)
        assert_array_equal(manual, auto)

        manual = cross_val(reg, X, y, cv=KFold(2))
        auto = cross_val(reg, X, y, cv=2)
        assert_array_equal(manual, auto)
コード例 #3
0
def test_search_light():
    """Test SlidingEstimator."""
    from sklearn.linear_model import Ridge, LogisticRegression
    from sklearn.pipeline import make_pipeline
    from sklearn.metrics import roc_auc_score, make_scorer
    with pytest.warns(None):  # NumPy module import
        from sklearn.ensemble import BaggingClassifier
    from sklearn.base import is_classifier

    logreg = LogisticRegression(solver='liblinear', multi_class='ovr',
                                random_state=0)

    X, y = make_data()
    n_epochs, _, n_time = X.shape
    # init
    pytest.raises(ValueError, SlidingEstimator, 'foo')
    sl = SlidingEstimator(Ridge())
    assert (not is_classifier(sl))
    sl = SlidingEstimator(LogisticRegression(solver='liblinear'))
    assert (is_classifier(sl))
    # fit
    assert_equal(sl.__repr__()[:18], '<SlidingEstimator(')
    sl.fit(X, y)
    assert_equal(sl.__repr__()[-28:], ', fitted with 10 estimators>')
    pytest.raises(ValueError, sl.fit, X[1:], y)
    pytest.raises(ValueError, sl.fit, X[:, :, 0], y)
    sl.fit(X, y, sample_weight=np.ones_like(y))

    # transforms
    pytest.raises(ValueError, sl.predict, X[:, :, :2])
    y_pred = sl.predict(X)
    assert (y_pred.dtype == int)
    assert_array_equal(y_pred.shape, [n_epochs, n_time])
    y_proba = sl.predict_proba(X)
    assert (y_proba.dtype == float)
    assert_array_equal(y_proba.shape, [n_epochs, n_time, 2])

    # score
    score = sl.score(X, y)
    assert_array_equal(score.shape, [n_time])
    assert (np.sum(np.abs(score)) != 0)
    assert (score.dtype == float)

    sl = SlidingEstimator(logreg)
    assert_equal(sl.scoring, None)

    # Scoring method
    for scoring in ['foo', 999]:
        sl = SlidingEstimator(logreg, scoring=scoring)
        sl.fit(X, y)
        pytest.raises((ValueError, TypeError), sl.score, X, y)

    # Check sklearn's roc_auc fix: scikit-learn/scikit-learn#6874
    # -- 3 class problem
    sl = SlidingEstimator(logreg, scoring='roc_auc')
    y = np.arange(len(X)) % 3
    sl.fit(X, y)
    pytest.raises(ValueError, sl.score, X, y)
    # -- 2 class problem not in [0, 1]
    y = np.arange(len(X)) % 2 + 1
    sl.fit(X, y)
    score = sl.score(X, y)
    assert_array_equal(score, [roc_auc_score(y - 1, _y_pred - 1)
                               for _y_pred in sl.decision_function(X).T])
    y = np.arange(len(X)) % 2

    # Cannot pass a metric as a scoring parameter
    sl1 = SlidingEstimator(logreg, scoring=roc_auc_score)
    sl1.fit(X, y)
    pytest.raises(ValueError, sl1.score, X, y)

    # Now use string as scoring
    sl1 = SlidingEstimator(logreg, scoring='roc_auc')
    sl1.fit(X, y)
    rng = np.random.RandomState(0)
    X = rng.randn(*X.shape)  # randomize X to avoid AUCs in [0, 1]
    score_sl = sl1.score(X, y)
    assert_array_equal(score_sl.shape, [n_time])
    assert (score_sl.dtype == float)

    # Check that scoring was applied adequately
    scoring = make_scorer(roc_auc_score, needs_threshold=True)
    score_manual = [scoring(est, x, y) for est, x in zip(
                    sl1.estimators_, X.transpose(2, 0, 1))]
    assert_array_equal(score_manual, score_sl)

    # n_jobs
    sl = SlidingEstimator(logreg, n_jobs=1, scoring='roc_auc')
    score_1job = sl.fit(X, y).score(X, y)
    sl.n_jobs = 2
    score_njobs = sl.fit(X, y).score(X, y)
    assert_array_equal(score_1job, score_njobs)
    sl.predict(X)

    # n_jobs > n_estimators
    sl.fit(X[..., [0]], y)
    sl.predict(X[..., [0]])

    # pipeline

    class _LogRegTransformer(LogisticRegression):
        # XXX needs transformer in pipeline to get first proba only
        def __init__(self):
            super(_LogRegTransformer, self).__init__()
            self.multi_class = 'ovr'
            self.random_state = 0
            self.solver = 'liblinear'

        def transform(self, X):
            return super(_LogRegTransformer, self).predict_proba(X)[..., 1]

    pipe = make_pipeline(SlidingEstimator(_LogRegTransformer()),
                         logreg)
    pipe.fit(X, y)
    pipe.predict(X)

    # n-dimensional feature space
    X = np.random.rand(10, 3, 4, 2)
    y = np.arange(10) % 2
    y_preds = list()
    for n_jobs in [1, 2]:
        pipe = SlidingEstimator(
            make_pipeline(Vectorizer(), logreg), n_jobs=n_jobs)
        y_preds.append(pipe.fit(X, y).predict(X))
        features_shape = pipe.estimators_[0].steps[0][1].features_shape_
        assert_array_equal(features_shape, [3, 4])
    assert_array_equal(y_preds[0], y_preds[1])

    # Bagging classifiers
    X = np.random.rand(10, 3, 4)
    for n_jobs in (1, 2):
        pipe = SlidingEstimator(BaggingClassifier(None, 2), n_jobs=n_jobs)
        pipe.fit(X, y)
        pipe.score(X, y)
        assert (isinstance(pipe.estimators_[0], BaggingClassifier))