Inzynierka/Lib/site-packages/sklearn/decomposition/tests/test_sparse_pca.py
2023-06-02 12:51:02 +02:00

384 lines
13 KiB
Python

# Author: Vlad Niculae
# License: BSD 3 clause
import sys
import pytest
import numpy as np
from numpy.testing import assert_array_equal
from sklearn.utils._testing import assert_array_almost_equal
from sklearn.utils._testing import assert_allclose
from sklearn.utils._testing import if_safe_multiprocessing_with_blas
from sklearn.decomposition import SparsePCA, MiniBatchSparsePCA, PCA
from sklearn.utils import check_random_state
def generate_toy_data(n_components, n_samples, image_size, random_state=None):
n_features = image_size[0] * image_size[1]
rng = check_random_state(random_state)
U = rng.randn(n_samples, n_components)
V = rng.randn(n_components, n_features)
centers = [(3, 3), (6, 7), (8, 1)]
sz = [1, 2, 1]
for k in range(n_components):
img = np.zeros(image_size)
xmin, xmax = centers[k][0] - sz[k], centers[k][0] + sz[k]
ymin, ymax = centers[k][1] - sz[k], centers[k][1] + sz[k]
img[xmin:xmax][:, ymin:ymax] = 1.0
V[k, :] = img.ravel()
# Y is defined by : Y = UV + noise
Y = np.dot(U, V)
Y += 0.1 * rng.randn(Y.shape[0], Y.shape[1]) # Add noise
return Y, U, V
# SparsePCA can be a bit slow. To avoid having test times go up, we
# test different aspects of the code in the same test
def test_correct_shapes():
rng = np.random.RandomState(0)
X = rng.randn(12, 10)
spca = SparsePCA(n_components=8, random_state=rng)
U = spca.fit_transform(X)
assert spca.components_.shape == (8, 10)
assert U.shape == (12, 8)
# test overcomplete decomposition
spca = SparsePCA(n_components=13, random_state=rng)
U = spca.fit_transform(X)
assert spca.components_.shape == (13, 10)
assert U.shape == (12, 13)
def test_fit_transform():
alpha = 1
rng = np.random.RandomState(0)
Y, _, _ = generate_toy_data(3, 10, (8, 8), random_state=rng) # wide array
spca_lars = SparsePCA(n_components=3, method="lars", alpha=alpha, random_state=0)
spca_lars.fit(Y)
# Test that CD gives similar results
spca_lasso = SparsePCA(n_components=3, method="cd", random_state=0, alpha=alpha)
spca_lasso.fit(Y)
assert_array_almost_equal(spca_lasso.components_, spca_lars.components_)
@if_safe_multiprocessing_with_blas
def test_fit_transform_parallel():
alpha = 1
rng = np.random.RandomState(0)
Y, _, _ = generate_toy_data(3, 10, (8, 8), random_state=rng) # wide array
spca_lars = SparsePCA(n_components=3, method="lars", alpha=alpha, random_state=0)
spca_lars.fit(Y)
U1 = spca_lars.transform(Y)
# Test multiple CPUs
spca = SparsePCA(
n_components=3, n_jobs=2, method="lars", alpha=alpha, random_state=0
).fit(Y)
U2 = spca.transform(Y)
assert not np.all(spca_lars.components_ == 0)
assert_array_almost_equal(U1, U2)
def test_transform_nan():
# Test that SparsePCA won't return NaN when there is 0 feature in all
# samples.
rng = np.random.RandomState(0)
Y, _, _ = generate_toy_data(3, 10, (8, 8), random_state=rng) # wide array
Y[:, 0] = 0
estimator = SparsePCA(n_components=8)
assert not np.any(np.isnan(estimator.fit_transform(Y)))
def test_fit_transform_tall():
rng = np.random.RandomState(0)
Y, _, _ = generate_toy_data(3, 65, (8, 8), random_state=rng) # tall array
spca_lars = SparsePCA(n_components=3, method="lars", random_state=rng)
U1 = spca_lars.fit_transform(Y)
spca_lasso = SparsePCA(n_components=3, method="cd", random_state=rng)
U2 = spca_lasso.fit(Y).transform(Y)
assert_array_almost_equal(U1, U2)
def test_initialization():
rng = np.random.RandomState(0)
U_init = rng.randn(5, 3)
V_init = rng.randn(3, 4)
model = SparsePCA(
n_components=3, U_init=U_init, V_init=V_init, max_iter=0, random_state=rng
)
model.fit(rng.randn(5, 4))
assert_allclose(model.components_, V_init / np.linalg.norm(V_init, axis=1)[:, None])
def test_mini_batch_correct_shapes():
rng = np.random.RandomState(0)
X = rng.randn(12, 10)
pca = MiniBatchSparsePCA(n_components=8, random_state=rng)
U = pca.fit_transform(X)
assert pca.components_.shape == (8, 10)
assert U.shape == (12, 8)
# test overcomplete decomposition
pca = MiniBatchSparsePCA(n_components=13, random_state=rng)
U = pca.fit_transform(X)
assert pca.components_.shape == (13, 10)
assert U.shape == (12, 13)
# XXX: test always skipped
@pytest.mark.skipif(True, reason="skipping mini_batch_fit_transform.")
def test_mini_batch_fit_transform():
alpha = 1
rng = np.random.RandomState(0)
Y, _, _ = generate_toy_data(3, 10, (8, 8), random_state=rng) # wide array
spca_lars = MiniBatchSparsePCA(n_components=3, random_state=0, alpha=alpha).fit(Y)
U1 = spca_lars.transform(Y)
# Test multiple CPUs
if sys.platform == "win32": # fake parallelism for win32
import joblib
_mp = joblib.parallel.multiprocessing
joblib.parallel.multiprocessing = None
try:
spca = MiniBatchSparsePCA(
n_components=3, n_jobs=2, alpha=alpha, random_state=0
)
U2 = spca.fit(Y).transform(Y)
finally:
joblib.parallel.multiprocessing = _mp
else: # we can efficiently use parallelism
spca = MiniBatchSparsePCA(n_components=3, n_jobs=2, alpha=alpha, random_state=0)
U2 = spca.fit(Y).transform(Y)
assert not np.all(spca_lars.components_ == 0)
assert_array_almost_equal(U1, U2)
# Test that CD gives similar results
spca_lasso = MiniBatchSparsePCA(
n_components=3, method="cd", alpha=alpha, random_state=0
).fit(Y)
assert_array_almost_equal(spca_lasso.components_, spca_lars.components_)
def test_scaling_fit_transform():
alpha = 1
rng = np.random.RandomState(0)
Y, _, _ = generate_toy_data(3, 1000, (8, 8), random_state=rng)
spca_lars = SparsePCA(n_components=3, method="lars", alpha=alpha, random_state=rng)
results_train = spca_lars.fit_transform(Y)
results_test = spca_lars.transform(Y[:10])
assert_allclose(results_train[0], results_test[0])
def test_pca_vs_spca():
rng = np.random.RandomState(0)
Y, _, _ = generate_toy_data(3, 1000, (8, 8), random_state=rng)
Z, _, _ = generate_toy_data(3, 10, (8, 8), random_state=rng)
spca = SparsePCA(alpha=0, ridge_alpha=0, n_components=2)
pca = PCA(n_components=2)
pca.fit(Y)
spca.fit(Y)
results_test_pca = pca.transform(Z)
results_test_spca = spca.transform(Z)
assert_allclose(
np.abs(spca.components_.dot(pca.components_.T)), np.eye(2), atol=1e-5
)
results_test_pca *= np.sign(results_test_pca[0, :])
results_test_spca *= np.sign(results_test_spca[0, :])
assert_allclose(results_test_pca, results_test_spca)
@pytest.mark.parametrize("SPCA", [SparsePCA, MiniBatchSparsePCA])
@pytest.mark.parametrize("n_components", [None, 3])
def test_spca_n_components_(SPCA, n_components):
rng = np.random.RandomState(0)
n_samples, n_features = 12, 10
X = rng.randn(n_samples, n_features)
model = SPCA(n_components=n_components).fit(X)
if n_components is not None:
assert model.n_components_ == n_components
else:
assert model.n_components_ == n_features
@pytest.mark.parametrize("SPCA", (SparsePCA, MiniBatchSparsePCA))
@pytest.mark.parametrize("method", ("lars", "cd"))
@pytest.mark.parametrize(
"data_type, expected_type",
(
(np.float32, np.float32),
(np.float64, np.float64),
(np.int32, np.float64),
(np.int64, np.float64),
),
)
def test_sparse_pca_dtype_match(SPCA, method, data_type, expected_type):
# Verify output matrix dtype
n_samples, n_features, n_components = 12, 10, 3
rng = np.random.RandomState(0)
input_array = rng.randn(n_samples, n_features).astype(data_type)
model = SPCA(n_components=n_components, method=method)
transformed = model.fit_transform(input_array)
assert transformed.dtype == expected_type
assert model.components_.dtype == expected_type
@pytest.mark.parametrize("SPCA", (SparsePCA, MiniBatchSparsePCA))
@pytest.mark.parametrize("method", ("lars", "cd"))
def test_sparse_pca_numerical_consistency(SPCA, method):
# Verify numericall consistentency among np.float32 and np.float64
rtol = 1e-3
alpha = 2
n_samples, n_features, n_components = 12, 10, 3
rng = np.random.RandomState(0)
input_array = rng.randn(n_samples, n_features)
model_32 = SPCA(
n_components=n_components, alpha=alpha, method=method, random_state=0
)
transformed_32 = model_32.fit_transform(input_array.astype(np.float32))
model_64 = SPCA(
n_components=n_components, alpha=alpha, method=method, random_state=0
)
transformed_64 = model_64.fit_transform(input_array.astype(np.float64))
assert_allclose(transformed_64, transformed_32, rtol=rtol)
assert_allclose(model_64.components_, model_32.components_, rtol=rtol)
@pytest.mark.parametrize("SPCA", [SparsePCA, MiniBatchSparsePCA])
def test_spca_feature_names_out(SPCA):
"""Check feature names out for *SparsePCA."""
rng = np.random.RandomState(0)
n_samples, n_features = 12, 10
X = rng.randn(n_samples, n_features)
model = SPCA(n_components=4).fit(X)
names = model.get_feature_names_out()
estimator_name = SPCA.__name__.lower()
assert_array_equal([f"{estimator_name}{i}" for i in range(4)], names)
# TODO (1.4): remove this test
def test_spca_n_iter_deprecation():
"""Check that we raise a warning for the deprecation of `n_iter` and it is ignored
when `max_iter` is specified.
"""
rng = np.random.RandomState(0)
n_samples, n_features = 12, 10
X = rng.randn(n_samples, n_features)
warn_msg = "'n_iter' is deprecated in version 1.1 and will be removed"
with pytest.warns(FutureWarning, match=warn_msg):
MiniBatchSparsePCA(n_iter=2).fit(X)
n_iter, max_iter = 1, 100
with pytest.warns(FutureWarning, match=warn_msg):
model = MiniBatchSparsePCA(
n_iter=n_iter, max_iter=max_iter, random_state=0
).fit(X)
assert model.n_iter_ > 1
assert model.n_iter_ <= max_iter
def test_pca_n_features_deprecation():
X = np.array([[-1, -1], [-2, -1], [-3, -2], [1, 1], [2, 1], [3, 2]])
pca = PCA(n_components=2).fit(X)
with pytest.warns(FutureWarning, match="`n_features_` was deprecated"):
pca.n_features_
def test_spca_early_stopping(global_random_seed):
"""Check that `tol` and `max_no_improvement` act as early stopping."""
rng = np.random.RandomState(global_random_seed)
n_samples, n_features = 50, 10
X = rng.randn(n_samples, n_features)
# vary the tolerance to force the early stopping of one of the model
model_early_stopped = MiniBatchSparsePCA(
max_iter=100, tol=0.5, random_state=global_random_seed
).fit(X)
model_not_early_stopped = MiniBatchSparsePCA(
max_iter=100, tol=1e-3, random_state=global_random_seed
).fit(X)
assert model_early_stopped.n_iter_ < model_not_early_stopped.n_iter_
# force the max number of no improvement to a large value to check that
# it does help to early stop
model_early_stopped = MiniBatchSparsePCA(
max_iter=100, tol=1e-6, max_no_improvement=2, random_state=global_random_seed
).fit(X)
model_not_early_stopped = MiniBatchSparsePCA(
max_iter=100, tol=1e-6, max_no_improvement=100, random_state=global_random_seed
).fit(X)
assert model_early_stopped.n_iter_ < model_not_early_stopped.n_iter_
def test_equivalence_components_pca_spca(global_random_seed):
"""Check the equivalence of the components found by PCA and SparsePCA.
Non-regression test for:
https://github.com/scikit-learn/scikit-learn/issues/23932
"""
rng = np.random.RandomState(global_random_seed)
X = rng.randn(50, 4)
n_components = 2
pca = PCA(
n_components=n_components,
svd_solver="randomized",
random_state=0,
).fit(X)
spca = SparsePCA(
n_components=n_components,
method="lars",
ridge_alpha=0,
alpha=0,
random_state=0,
).fit(X)
assert_allclose(pca.components_, spca.components_)
def test_sparse_pca_inverse_transform():
"""Check that `inverse_transform` in `SparsePCA` and `PCA` are similar."""
rng = np.random.RandomState(0)
n_samples, n_features = 10, 5
X = rng.randn(n_samples, n_features)
n_components = 2
spca = SparsePCA(
n_components=n_components, alpha=1e-12, ridge_alpha=1e-12, random_state=0
)
pca = PCA(n_components=n_components, random_state=0)
X_trans_spca = spca.fit_transform(X)
X_trans_pca = pca.fit_transform(X)
assert_allclose(
spca.inverse_transform(X_trans_spca), pca.inverse_transform(X_trans_pca)
)
@pytest.mark.parametrize("SPCA", [SparsePCA, MiniBatchSparsePCA])
def test_transform_inverse_transform_round_trip(SPCA):
"""Check the `transform` and `inverse_transform` round trip with no loss of
information.
"""
rng = np.random.RandomState(0)
n_samples, n_features = 10, 5
X = rng.randn(n_samples, n_features)
n_components = n_features
spca = SPCA(
n_components=n_components, alpha=1e-12, ridge_alpha=1e-12, random_state=0
)
X_trans_spca = spca.fit_transform(X)
assert_allclose(spca.inverse_transform(X_trans_spca), X)