def test_embedding_default():
# Make sure the embedding works by default.
X, y = iris.data, iris.target
clf = MLPClassifier(n_epochs=1)
clf.fit(X, y)
assert clf.transform(X).shape[1] == 256
def test_embedding_no_layers():
# Make sure the embedding works with no layers.
X, y = iris.data, iris.target
clf = MLPClassifier(n_epochs=1, hidden_units=[])
clf.fit(X, y)
assert clf.transform(X).shape[1] == np.unique(y).shape[0]
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_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_embedding_specific_layer():
# Make sure the embedding works with no layers.
X, y = iris.data, iris.target
clf = MLPClassifier(n_epochs=1,
hidden_units=(256, 8, 256),
transform_layer_index=1)
clf.fit(X, y)
assert clf.transform(X).shape[1] == 8
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_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_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_alpha_dropout_and_selu():
"""Test binary classification with SEUL and alpha dropout."""
# Check that predictions are deterministic.
clf = MLPClassifier(keep_prob=0.7, activation=nn.selu, **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=0.7, activation=nn.selu, **KWARGS), X, Y1)
check_predictions(
MLPClassifier(keep_prob=0.7, activation=nn.selu, **KWARGS), X_sp, Y1)
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_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_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_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)
