def test_multiple_layers():
for n_layers in range(3):
clf = MLPClassifier(hidden_units=(8,) * n_layers, **KWARGS)
target = iris.target_names[iris.target]
clf.fit(iris.data, target)
y_pred = clf.predict(iris.data)
accuracy = accuracy_score(target, y_pred)
# Just make sure the model doesn't crash and isn't terrible.
assert accuracy > 0.9, \
"low accuracy ({}) with {} layers".format(accuracy, n_layers)
def test_persistence():
"""Test that models can be pickled and reloaded."""
clf = MLPClassifier(random_state=42)
target = iris.target_names[iris.target]
clf.fit(iris.data, target)
probs1 = clf.predict_proba(iris.data)
b = BytesIO()
pickle.dump(clf, b)
clf2 = pickle.loads(b.getvalue())
probs2 = clf2.predict_proba(iris.data)
assert_array_almost_equal(probs1, probs2)
def test_refitting():
# Check that fitting twice works (e.g., to make sure that fit-related
# variables are cleared appropriately when refitting).
X, y = iris.data, iris.target
clf = MLPClassifier(n_epochs=1)
clf.fit(X, y)
assert np.array_equal(clf.classes_, np.unique(y))
y_binary = (y == y[0]).astype(float)
clf.fit(X, y_binary)
assert np.array_equal(clf.classes_, np.unique(y_binary))
def test_dropout():
"""Test binary classification."""
# Check that predictions are deterministic.
clf = MLPClassifier(keep_prob=0.5, **KWARGS)
clf.fit(X_sp, Y1)
y_pred1 = clf.predict_proba(X_sp)
for _ in range(100):
y_pred_i = clf.predict_proba(X_sp)
assert_array_almost_equal(y_pred1, y_pred_i)
check_predictions(
MLPClassifier(keep_prob=0.5, **KWARGS), X, Y1)
check_predictions(
MLPClassifier(keep_prob=0.5, **KWARGS), X_sp, Y1)
def test_cross_val_predict():
# Make sure it works in cross_val_predict for multiclass.
X, y = load_iris(return_X_y=True)
y = LabelBinarizer().fit_transform(y)
X = StandardScaler().fit_transform(X)
mlp = MLPClassifier(n_epochs=10,
solver_kwargs={'learning_rate': 0.05},
random_state=4567).fit(X, y)
cv = KFold(n_splits=4, random_state=457, shuffle=True)
y_oos = cross_val_predict(mlp, X, y, cv=cv, method='predict_proba')
auc = roc_auc_score(y, y_oos, average=None)
assert np.all(auc >= 0.96)
def test_refitting():
# Check that fitting twice works (e.g., to make sure that fit-related
# variables are cleared appropriately when refitting).
X, y = iris.data, iris.target
clf = MLPClassifier(n_epochs=1)
clf.fit(X, y)
assert np.array_equal(clf.classes_, np.unique(y))
y_binary = (y == y[0]).astype(float)
clf.fit(X, y_binary)
assert np.array_equal(clf.classes_, np.unique(y_binary))
def test_partial_fit():
X, y = iris.data, iris.target
# Predict on the training set and check that it (over)fit as expected.
clf = MLPClassifier(n_epochs=1)
for _ in range(30):
clf.partial_fit(X, y)
y_pred = clf.predict(X)
assert ((y_pred - y) ** 2).mean() < 10
# Check that the classes argument works.
clf = MLPClassifier(n_epochs=1)
clf.partial_fit(X[:10], y[:10], classes=np.unique(y))
for _ in range(30):
clf.partial_fit(X, y)
# Check that using the classes argument wrong will fail.
with pytest.raises(ValueError):
clf = MLPClassifier(n_epochs=1)
clf.partial_fit(X, y, classes=np.array([0, 1]))
def test_replicability():
clf = MLPClassifier(keep_prob=0.5, random_state=42)
target = iris.target_names[iris.target]
probs1 = clf.fit(iris.data, target).predict_proba(iris.data)
probs2 = clf.fit(iris.data, target).predict_proba(iris.data)
assert_array_almost_equal(probs1, probs2)
def test_feed_dict():
# Note that `tf.nn.dropout` scales the input up by t_dropout during
# training so that scaling down during prediction isn't needed.
# https://github.com/tensorflow/tensorflow/blob/2e152ecd67b3c5080f417260bc751e0c6bd7f1d3/tensorflow/python/ops/nn_ops.py#L1081-L1082.
# Instantiate an MLP and mock out things that would be set in fit.
mlp = MLPClassifier(keep_prob=0.5)
mlp.input_targets_ = "input_targets"
mlp._input_indices = "input_indices"
mlp._input_values = "input_values"
mlp._input_shape = "input_shape"
mlp._keep_prob = "t_keep_prob"
mlp._sample_weight = "sample_weight"
# sparse, targets given for training
mlp.is_sparse_ = True
X_sparse = MagicMock()
X_sparse_dok = MagicMock()
X_sparse.todok.return_value = X_sparse_dok
X_sparse_dok.nnz = 100
y = MagicMock()
fd = mlp._make_feed_dict(X_sparse, y)
expected_keys = {'input_shape', 'input_values', 'input_indices',
'input_targets', 't_keep_prob', 'sample_weight'}
assert set(fd.keys()) == expected_keys
assert fd['t_keep_prob'] == 0.5
# sparse, no targets given
fd = mlp._make_feed_dict(X_sparse)
expected_keys = {'input_shape', 'input_values', 'input_indices',
't_keep_prob', 'sample_weight'}
assert set(fd.keys()) == expected_keys
assert fd['t_keep_prob'] == 1.0
# dense, targets given for training
mlp.is_sparse_ = False
X_dense = MagicMock()
fd = mlp._make_feed_dict(X_dense, y)
expected_keys = {'input_values', 't_keep_prob', 'input_targets',
'sample_weight'}
assert set(fd.keys()) == expected_keys
assert fd['t_keep_prob'] == 0.5
# dense, no targets given
fd = mlp._make_feed_dict(X_dense)
expected_keys = {'input_values', 't_keep_prob', 'sample_weight'}
assert set(fd.keys()) == expected_keys
assert fd['t_keep_prob'] == 1.0
def test_predict_3_classes():
"""Test multiclass classification."""
check_predictions(MLPClassifier(**KWARGS), X, Y2)
check_predictions(MLPClassifier(**KWARGS), X_sp, Y2)
def test_predict_2_classes():
"""Test binary classification."""
check_predictions(MLPClassifier(**KWARGS), X, Y1)
check_predictions(MLPClassifier(**KWARGS), X_sp, Y1)
def test_multilabel():
check_multilabel_predictions(MLPClassifier(**KWARGS), X, Y_multilabel)
check_multilabel_predictions(MLPClassifier(**KWARGS), X_sp, Y_multilabel)
def test_partial_fit():
X, y = iris.data, iris.target
# Predict on the training set and check that it (over)fit as expected.
clf = MLPClassifier(n_epochs=1)
for _ in range(30):
clf.partial_fit(X, y)
y_pred = clf.predict(X)
assert ((y_pred - y) ** 2).mean() < 10
# Check that the classes argument works.
clf = MLPClassifier(n_epochs=1)
clf.partial_fit(X[:10], y[:10], classes=np.unique(y))
for _ in range(30):
clf.partial_fit(X, y)
# Check that using the classes argument wrong will fail.
with pytest.raises(ValueError):
clf = MLPClassifier(n_epochs=1)
clf.partial_fit(X, y, classes=np.array([0, 1]))
def test_replicability():
clf = MLPClassifier(keep_prob=0.5, random_state=42)
target = iris.target_names[iris.target]
probs1 = clf.fit(iris.data, target).predict_proba(iris.data)
probs2 = clf.fit(iris.data, target).predict_proba(iris.data)
assert_array_almost_equal(probs1, probs2)
def test_sample_weight(make_dataset_func, dataset_kwargs):
"""Ensure we handle sample weights for all classification problems."""
assert_sample_weights_work(
make_dataset_func, dataset_kwargs, lambda: MLPClassifier(
n_epochs=30, random_state=42, keep_prob=0.8, hidden_units=(128, )))
def test_prediction_gradient():
"""Test computation of prediction gradients."""
# Binary classification
n_classes = 1
mlp = MLPClassifier(n_epochs=100, random_state=42, hidden_units=(5,))
X, y = make_classification(
n_samples=1000, n_features=20, n_informative=n_classes, n_redundant=0,
n_classes=n_classes, n_clusters_per_class=1, shuffle=False)
mlp.fit(X, y)
grad = mlp.prediction_gradient(X)
grad_means = grad.mean(axis=0)
assert grad.shape == X.shape
# Check that only the informative feature has a large gradient.
# The values of 1 and 0.5 here are somewhat arbitrary but should serve as
# a regression test if nothing else.
assert np.abs(grad_means[0]) > 1.
for m in grad_means[1:]:
assert np.abs(m) < 0.5
# Multiclass classification: here, we'll just check that it runs and that
# the output is the right shape.
n_classes = 5
X, y = make_classification(
n_samples=1000, n_features=20, n_informative=n_classes,
n_redundant=0, n_classes=n_classes, n_clusters_per_class=1,
shuffle=False)
mlp.fit(X, y)
grad = mlp.prediction_gradient(X)
assert grad.shape == (X.shape[0], n_classes, X.shape[1])
# Multilabel binary classification.
X, y = make_multilabel_classification(
n_samples=1000, random_state=42, n_classes=n_classes)
mlp.fit(X, y)
grad = mlp.prediction_gradient(X)
assert grad.shape == (X.shape[0], n_classes, X.shape[1])
# Raise an exception for sparse inputs, which are not yet supported.
X_sp = sp.csr_matrix(X)
mlp.fit(X_sp, y)
with pytest.raises(NotImplementedError):
mlp.prediction_gradient(X_sp)
def test_feed_dict():
# Note that `tf.nn.dropout` scales the input up by t_dropout during
# training so that scaling down during prediction isn't needed.
# https://github.com/tensorflow/tensorflow/blob/2e152ecd67b3c5080f417260bc751e0c6bd7f1d3/tensorflow/python/ops/nn_ops.py#L1081-L1082.
# Instantiate an MLP and mock out things that would be set in fit.
mlp = MLPClassifier(keep_prob=0.5)
mlp.input_targets_ = "input_targets"
mlp._input_indices = "input_indices"
mlp._input_values = "input_values"
mlp._input_shape = "input_shape"
mlp._keep_prob = "t_keep_prob"
# sparse, targets given for training
mlp.is_sparse_ = True
X_sparse = MagicMock()
X_sparse_dok = MagicMock()
X_sparse.todok.return_value = X_sparse_dok
X_sparse_dok.nnz = 100
y = MagicMock()
fd = mlp._make_feed_dict(X_sparse, y)
expected_keys = {'input_shape', 'input_values', 'input_indices',
'input_targets', 't_keep_prob'}
assert set(fd.keys()) == expected_keys
assert fd['t_keep_prob'] == 0.5
# sparse, no targets given
fd = mlp._make_feed_dict(X_sparse)
expected_keys = {'input_shape', 'input_values', 'input_indices',
't_keep_prob'}
assert set(fd.keys()) == expected_keys
assert fd['t_keep_prob'] == 1.0
# dense, targets given for training
mlp.is_sparse_ = False
X_dense = MagicMock()
fd = mlp._make_feed_dict(X_dense, y)
expected_keys = {'input_values', 't_keep_prob', 'input_targets'}
assert set(fd.keys()) == expected_keys
assert fd['t_keep_prob'] == 0.5
# dense, no targets given
fd = mlp._make_feed_dict(X_dense)
expected_keys = {'input_values', 't_keep_prob'}
assert set(fd.keys()) == expected_keys
assert fd['t_keep_prob'] == 1.0