def test_weights():
sparse_X = 1
X, y = build_dataset(n_samples=30, n_features=50, sparse_X=sparse_X)
np.random.seed(0)
weights = np.abs(np.random.randn(X.shape[1]))
tol = 1e-14
params = {'n_alphas': 10, 'tol': tol}
alphas1, coefs1, gaps1 = celer_path(X,
y,
"lasso",
weights=weights,
verbose=1,
**params)
alphas2, coefs2, gaps2 = celer_path(X / weights[None, :], y, "lasso",
**params)
assert_allclose(alphas1, alphas2)
assert_allclose(coefs1, coefs2 / weights[:, None], atol=1e-4, rtol=1e-3)
assert_array_less(gaps1, tol * norm(y)**2 / len(y))
assert_array_less(gaps2, tol * norm(y)**2 / len(y))
alpha = 0.001
clf1 = Lasso(alpha=alpha, weights=weights, fit_intercept=False).fit(X, y)
clf2 = Lasso(alpha=alpha, fit_intercept=False).fit(X / weights, y)
assert_allclose(clf1.coef_, clf2.coef_ / weights)
# weights must be > 0
clf1.weights[0] = 0.
np.testing.assert_raises(ValueError, clf1.fit, X=X, y=y)
def test_convergence_warning():
X, y = build_dataset(n_samples=10, n_features=10)
tol = -1 # gap canot be negative, a covnergence warning should be raised
alpha_max = np.max(np.abs(X.T.dot(y))) / X.shape[0]
clf = Lasso(alpha_max / 10, max_iter=1, max_epochs=100, tol=tol)
with warnings.catch_warnings(record=True) as w:
# Cause all warnings to always be triggered.
warnings.simplefilter("always")
clf.fit(X, y)
assert len(w) == 1
assert issubclass(w[-1].category, ConvergenceWarning)
def test_dropin_lasso(sparse_X):
"""Test that our Lasso class behaves as sklearn's Lasso."""
X, y, _, _ = build_dataset(n_samples=20, n_features=30, sparse_X=sparse_X)
alpha_max = np.linalg.norm(X.T.dot(y), ord=np.inf) / X.shape[0]
alpha = alpha_max / 2.
clf = Lasso(alpha=alpha)
clf.fit(X, y)
clf2 = sklearn_Lasso(alpha=alpha)
clf2.fit(X, y)
np.testing.assert_allclose(clf.coef_, clf2.coef_, rtol=1e-5)
check_estimator(Lasso)
def test_dropin_lasso(sparse_X, fit_intercept):
"""Test that our Lasso class behaves as sklearn's Lasso."""
X, y, _, _ = build_dataset(n_samples=20, n_features=30, sparse_X=sparse_X)
alpha_max = np.linalg.norm(X.T.dot(y), ord=np.inf) / X.shape[0]
alpha = alpha_max / 2.
params = dict(alpha=alpha,
fit_intercept=fit_intercept,
tol=1e-10,
normalize=True)
clf = Lasso(**params)
clf.fit(X, y)
clf2 = sklearn_Lasso(**params)
clf2.fit(X, y)
np.testing.assert_allclose(clf.coef_, clf2.coef_, rtol=1e-5)
if fit_intercept:
np.testing.assert_allclose(clf.intercept_, clf2.intercept_)
check_estimator(Lasso)
def test_zero_iter():
X, y = build_dataset(n_samples=30, n_features=50)
# convergence warning is raised bc we return -1 as gap
with warnings.catch_warnings(record=True):
assert_allclose(Lasso(max_iter=0).fit(X, y).coef_, 0)
y = 2 * (y > 0) - 1
assert_allclose(
LogisticRegression(max_iter=0, solver="celer-pn").fit(X, y).coef_,
0)
assert_allclose(
LogisticRegression(max_iter=0, solver="celer").fit(X, y).coef_, 0)
def test_Lasso(sparse_X, fit_intercept, positive):
"""Test that our Lasso class behaves as sklearn's Lasso."""
X, y = build_dataset(n_samples=20, n_features=30, sparse_X=sparse_X)
if not positive:
alpha_max = norm(X.T.dot(y), ord=np.inf) / X.shape[0]
else:
alpha_max = X.T.dot(y).max() / X.shape[0]
alpha = alpha_max / 2.
params = dict(alpha=alpha,
fit_intercept=fit_intercept,
tol=1e-10,
positive=positive)
clf = Lasso(**params)
clf.fit(X, y)
clf2 = sklearn_Lasso(**params)
clf2.fit(X, y)
assert_allclose(clf.coef_, clf2.coef_, rtol=1e-5)
if fit_intercept:
assert_allclose(clf.intercept_, clf2.intercept_)
def test_warm_start():
"""Test Lasso path convergence."""
X, y = build_dataset(n_samples=100, n_features=100, sparse_X=True)
n_samples, n_features = X.shape
alpha_max = np.max(np.abs(X.T.dot(y))) / n_samples
n_alphas = 10
alphas = alpha_max * np.logspace(0, -2, n_alphas)
reg1 = Lasso(tol=1e-6, warm_start=True, p0=10)
reg1.coef_ = np.zeros(n_features)
for alpha in alphas:
reg1.set_params(alpha=alpha)
reg1.fit(X, y)
# refitting with warm start should take less than 2 iters:
reg1.fit(X, y)
# hack because assert_array_less does strict comparison...
np.testing.assert_array_less(reg1.n_iter_, 2.01)