def test_loss(self):
"""Test longitudinal multinomial model loss."""
X, _, _ = LongitudinalFeaturesLagger(n_lags=self.n_lags)\
.fit_transform(self.X)
model = ModelSCCS(n_intervals=2, n_lags=self.n_lags)\
.fit(X, self.y)
loss = model.loss(coeffs=np.array([0.0, 0.0, 1.0, 0.0]))
expected_loss = -np.log((np.e / (2 * np.e) * 1 / (1 + np.e))) / 2
self.assertAlmostEqual(loss, expected_loss)
def test_grad(self):
"""Test longitudinal multinomial model gradient value."""
X = [np.array([[0, 0.], [1, 0]]), np.array([[1, 0.], [0, 1]])]
X, _, _ = LongitudinalFeaturesLagger(n_lags=self.n_lags) \
.fit_transform(X)
model = ModelSCCS(n_intervals=2, n_lags=self.n_lags) \
.fit(X, self.y)
grad = model.grad(coeffs=np.array([0.0, 0.0, 1.0, 0.0]))
expected_grad = -np.array([
-1 / 2 - 1 / (1 + np.e), 1 - np.e / (1 + np.e), 1 - np.e /
(1 + np.e), 0
]) / 2
np.testing.assert_almost_equal(grad, expected_grad, decimal=15)
def test_grad_loss_consistency(self):
"""Test longitudinal multinomial model gradient properties."""
n_intervals = 16
n_lags = 4
sim = SimuSCCS(500, n_intervals, 3, n_lags, None,
True, "infinite", seed=42, verbose=False)
X, y, censoring, coeffs = sim.simulate()
X = LongitudinalFeaturesLagger(n_lags=n_lags) \
.fit_transform(X, censoring)
model = ModelSCCS(n_intervals=n_intervals, n_lags=n_lags) \
.fit(X, y, censoring)
self._test_grad(model, coeffs)
X_sparse = [csr_matrix(x) for x in X]
model = ModelSCCS(n_intervals=n_intervals, n_lags=n_lags) \
.fit(X_sparse, y, censoring)
self._test_grad(model, coeffs)
def test_lipschitz_constant(self):
"""Test longitudinal multinomial model Lipschitz constant."""
X = [
np.array([[0, 0, 1], [0, 1, 1], [1, 1, 1]], dtype="float64"),
np.array([[0, 1, 1], [0, 1, 1], [1, 1, 1]], dtype="float64")
]
y = [
np.array([0, 1, 0], dtype="int32"),
np.array([0, 1, 0], dtype="int32")
]
n_lags = np.repeat(1, 3).astype(dtype="uint64")
X, _, _ = LongitudinalFeaturesLagger(n_lags=n_lags) \
.fit_transform(X)
model = ModelSCCS(n_intervals=3, n_lags=n_lags).fit(X, y)
lip_constant = model.get_lip_max()
expected_lip_constant = .5
self.assertEqual(lip_constant, expected_lip_constant)
def test_convergence_with_lags(self):
"""Test longitudinal multinomial model convergence."""
n_intervals = 10
n_lags = 3
n_samples = 1500
n_features = 3
sim = SimuSCCS(n_samples, n_intervals, n_features, n_lags, None,
True, "short", seed=42, verbose=False)
X, y, censoring, coeffs = sim.simulate()
X = LongitudinalFeaturesLagger(n_lags=n_lags) \
.fit_transform(X, censoring)
model = ModelSCCS(n_intervals=n_intervals,
n_lags=n_lags).fit(X, y, censoring)
solver = SVRG(max_iter=15, verbose=False)
solver.set_model(model).set_prox(ProxZero())
coeffs_svrg = solver.solve(step=1 / model.get_lip_max())
np.testing.assert_almost_equal(coeffs, coeffs_svrg, decimal=1)
def test_grad_loss_consistency(self):
"""Test longitudinal multinomial model gradient properties."""
n_lags = np.repeat(9, 3).astype(dtype="uint64")
sim = SimuSCCS(500,
36,
3,
n_lags,
None,
"single_exposure",
seed=42,
verbose=False)
_, X, y, censoring, coeffs = sim.simulate()
coeffs = np.hstack(coeffs)
X, _, _ = LongitudinalFeaturesLagger(n_lags=n_lags) \
.fit_transform(X, censoring)
model = ModelSCCS(n_intervals=36, n_lags=n_lags)\
.fit(X, y, censoring)
self._test_grad(model, coeffs)
X_sparse = [csr_matrix(x) for x in X]
model = ModelSCCS(n_intervals=36, n_lags=n_lags)\
.fit(X_sparse, y, censoring)
self._test_grad(model, coeffs)
def test_convergence_with_lags(self):
"""Test longitudinal multinomial model convergence."""
n_intervals = 10
n_samples = 800
n_features = 2
n_lags = np.repeat(2, n_features).astype(dtype="uint64")
sim = SimuSCCS(n_samples,
n_intervals,
n_features,
n_lags,
None,
"multiple_exposures",
seed=42)
_, X, y, censoring, coeffs = sim.simulate()
coeffs = np.hstack(coeffs)
X, _, _ = LongitudinalFeaturesLagger(n_lags=n_lags) \
.fit_transform(X, censoring)
model = ModelSCCS(n_intervals=n_intervals,
n_lags=n_lags).fit(X, y, censoring)
solver = SVRG(max_iter=15, verbose=False)
solver.set_model(model).set_prox(ProxZero())
coeffs_svrg = solver.solve(step=1 / model.get_lip_max())
np.testing.assert_almost_equal(coeffs, coeffs_svrg, decimal=1)
def test_sccs_serialize_and_compare(self):
"""Test serialization (cereal/pickle) of SCCS."""
X = [
np.array([[0, 0, 1], [0, 1, 1], [1, 1, 1]], dtype="float64"),
np.array([[0, 1, 1], [0, 1, 1], [1, 1, 1]], dtype="float64")
]
y = [
np.array([0, 1, 0], dtype="int32"),
np.array([0, 1, 0], dtype="int32")
]
n_lags = np.repeat(1, 3).astype(dtype="uint64")
X, _, _ = LongitudinalFeaturesLagger(n_lags=n_lags) \
.fit_transform(X)
model = ModelSCCS(n_intervals=3, n_lags=n_lags).fit(X, y)
pickled = pickle.loads(pickle.dumps(model))
self.assertTrue(model._model.compare(pickled._model))
def _construct_model_obj(self):
return ModelSCCS(self.n_intervals, self.n_lags)