Python源码示例：sklearn.decomposition.SparsePCA()
示例1
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
示例2
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,
normalize_components=True)
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)
示例3
def dim_reduction_method(self):
"""
select dimensionality reduction method
"""
if self.dim_reduction=='pca':
return PCA()
elif self.dim_reduction=='factor-analysis':
return FactorAnalysis()
elif self.dim_reduction=='fast-ica':
return FastICA()
elif self.dim_reduction=='kernel-pca':
return KernelPCA()
elif self.dim_reduction=='sparse-pca':
return SparsePCA()
elif self.dim_reduction=='truncated-svd':
return TruncatedSVD()
elif self.dim_reduction!=None:
raise ValueError('%s is not a supported dimensionality reduction method. Valid inputs are: \
"pca","factor-analysis","fast-ica,"kernel-pca","sparse-pca","truncated-svd".'
%(self.dim_reduction))
示例4
def test_objectmapper(self):
df = pdml.ModelFrame([])
self.assertIs(df.decomposition.PCA, decomposition.PCA)
self.assertIs(df.decomposition.IncrementalPCA,
decomposition.IncrementalPCA)
self.assertIs(df.decomposition.KernelPCA, decomposition.KernelPCA)
self.assertIs(df.decomposition.FactorAnalysis,
decomposition.FactorAnalysis)
self.assertIs(df.decomposition.FastICA, decomposition.FastICA)
self.assertIs(df.decomposition.TruncatedSVD, decomposition.TruncatedSVD)
self.assertIs(df.decomposition.NMF, decomposition.NMF)
self.assertIs(df.decomposition.SparsePCA, decomposition.SparsePCA)
self.assertIs(df.decomposition.MiniBatchSparsePCA,
decomposition.MiniBatchSparsePCA)
self.assertIs(df.decomposition.SparseCoder, decomposition.SparseCoder)
self.assertIs(df.decomposition.DictionaryLearning,
decomposition.DictionaryLearning)
self.assertIs(df.decomposition.MiniBatchDictionaryLearning,
decomposition.MiniBatchDictionaryLearning)
self.assertIs(df.decomposition.LatentDirichletAllocation,
decomposition.LatentDirichletAllocation)
示例5
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
示例6
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_)
# Test that deprecated ridge_alpha parameter throws warning
warning_msg = "The ridge_alpha parameter on transform()"
assert_warns_message(DeprecationWarning, warning_msg, spca_lars.transform,
Y, ridge_alpha=0.01)
assert_warns_message(DeprecationWarning, warning_msg, spca_lars.transform,
Y, ridge_alpha=None)
示例7
def test_correct_shapes(norm_comp):
rng = np.random.RandomState(0)
X = rng.randn(12, 10)
spca = SparsePCA(n_components=8, random_state=rng,
normalize_components=norm_comp)
U = spca.fit_transform(X)
assert_equal(spca.components_.shape, (8, 10))
assert_equal(U.shape, (12, 8))
# test overcomplete decomposition
spca = SparsePCA(n_components=13, random_state=rng,
normalize_components=norm_comp)
U = spca.fit_transform(X)
assert_equal(spca.components_.shape, (13, 10))
assert_equal(U.shape, (12, 13))
示例8
def test_fit_transform(norm_comp):
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, normalize_components=norm_comp)
spca_lars.fit(Y)
# Test that CD gives similar results
spca_lasso = SparsePCA(n_components=3, method='cd', random_state=0,
alpha=alpha, normalize_components=norm_comp)
spca_lasso.fit(Y)
assert_array_almost_equal(spca_lasso.components_, spca_lars.components_)
示例9
def test_fit_transform_parallel(norm_comp):
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, normalize_components=norm_comp)
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, normalize_components=norm_comp).fit(Y)
U2 = spca.transform(Y)
assert not np.all(spca_lars.components_ == 0)
assert_array_almost_equal(U1, U2)
示例10
def test_transform_nan(norm_comp):
# 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, normalize_components=norm_comp)
assert not np.any(np.isnan(estimator.fit_transform(Y)))
示例11
def test_initialization(norm_comp):
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, normalize_components=norm_comp)
model.fit(rng.randn(5, 4))
if norm_comp:
assert_allclose(model.components_,
V_init / np.linalg.norm(V_init, axis=1)[:, None])
else:
assert_allclose(model.components_, V_init)
示例12
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, normalize_components=True)
results_train = spca_lars.fit_transform(Y)
results_test = spca_lars.transform(Y[:10])
assert_allclose(results_train[0], results_test[0])
示例13
def spca(components, train_matrix, test_matrix):
"""Sparse principal component analysis routine.
Parameters
----------
components : int
The number of components to be returned.
train_matrix : array
The training features.
test_matrix : array
The test features.
Returns
-------
new_train : array
Extracted training features.
new_test : array
Extracted test features.
"""
msg = 'The number of components must be a positive int greater than 0.'
assert components > 0, msg
pca = SparsePCA(n_components=components)
model = pca.fit(X=train_matrix)
new_train = model.transform(train_matrix)
new_test = model.transform(test_matrix)
return new_train, new_test
示例14
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_equal(spca.components_.shape, (8, 10))
assert_equal(U.shape, (12, 8))
# test overcomplete decomposition
spca = SparsePCA(n_components=13, random_state=rng)
U = spca.fit_transform(X)
assert_equal(spca.components_.shape, (13, 10))
assert_equal(U.shape, (12, 13))
示例15
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_true(not np.all(spca_lars.components_ == 0))
assert_array_almost_equal(U1, U2)
示例16
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_false(np.any(np.isnan(estimator.fit_transform(Y))))
示例17
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_array_equal(model.components_, V_init)
