def test_fit_transform():
"""Test fit_transform method for class ConnectivityMeasure"""
n_subjects = 10
n_features = 49
n_samples = 200
# Generate signals and compute empirical covariances
covs = []
signals = []
random_state = check_random_state(0)
for k in range(n_subjects):
signal = random_state.randn(n_samples, n_features)
signals.append(signal)
signal -= signal.mean(axis=0)
covs.append((signal.T).dot(signal) / n_samples)
input_covs = copy.copy(covs)
kinds = ["correlation", "tangent", "precision",
"partial correlation"]
for kind in kinds:
conn_measure = ConnectivityMeasure(kind=kind,
cov_estimator=EmpiricalCovariance())
connectivities = conn_measure.fit_transform(signals)
# Generic
assert_true(isinstance(connectivities, np.ndarray))
assert_equal(len(connectivities), len(covs))
for k, cov_new in enumerate(connectivities):
assert_array_equal(input_covs[k], covs[k])
assert(is_spd(covs[k], decimal=7))
# Positive definiteness if expected and output value checks
if kind == "tangent":
assert_array_almost_equal(cov_new, cov_new.T)
gmean_sqrt = _map_eigenvalues(np.sqrt,
conn_measure.mean_)
assert(is_spd(gmean_sqrt, decimal=7))
assert(is_spd(conn_measure.whitening_, decimal=7))
assert_array_almost_equal(conn_measure.whitening_.dot(
gmean_sqrt), np.eye(n_features))
assert_array_almost_equal(gmean_sqrt.dot(
_map_eigenvalues(np.exp, cov_new)).dot(gmean_sqrt),
covs[k])
elif kind == "precision":
assert(is_spd(cov_new, decimal=7))
assert_array_almost_equal(cov_new.dot(covs[k]),
np.eye(n_features))
elif kind == "correlation":
assert(is_spd(cov_new, decimal=7))
d = np.sqrt(np.diag(np.diag(covs[k])))
assert_array_almost_equal(d.dot(cov_new).dot(d), covs[k])
elif kind == "partial correlation":
prec = linalg.inv(covs[k])
d = np.sqrt(np.diag(np.diag(prec)))
assert_array_almost_equal(d.dot(cov_new).dot(d), -prec +
2 * np.diag(np.diag(prec)))
def test_confounds_connectome_measure():
n_subjects = 10
n_features = 49
# Generate signals and compute covariances and apply confounds while
# computing covariances
signals = []
for k in range(n_subjects):
n_samples = 200 + k
signal, _, confounds = generate_signals(n_features=n_features,
n_confounds=5,
length=n_samples,
same_variance=False)
signals.append(signal)
correlation_measure = ConnectivityMeasure(kind='correlation',
vectorize=True)
# Clean confounds on 10 subjects with confounds filtered to 10 subjects in
# length
cleaned_vectors = correlation_measure.fit_transform(
signals, confounds=confounds[0:10])
zero_matrix = np.zeros((confounds.shape[1], cleaned_vectors.shape[1]))
assert_array_almost_equal(np.dot(confounds[0:10].T, cleaned_vectors),
zero_matrix)
assert (isinstance(cleaned_vectors, np.ndarray))
# Confounds as pandas DataFrame
confounds_df = DataFrame(confounds[0:10])
cleaned_vectors_df = correlation_measure.fit_transform(
signals, confounds=confounds_df)
# Raising error for input confounds are not iterable
conn_measure = ConnectivityMeasure(vectorize=True)
pytest.raises(ValueError, conn_measure._check_input, signals, confounds=1.)
pytest.raises(ValueError,
conn_measure._fit_transform,
X=signals,
do_fit=True,
do_transform=True,
confounds=1.)
pytest.raises(ValueError, conn_measure.fit_transform, signals, None, 1.)
# Raising error for input confounds are given but not vectorize=True
conn_measure = ConnectivityMeasure(vectorize=False)
pytest.raises(ValueError, conn_measure.fit_transform, signals, None,
confounds[0:10])
def test_connectivity_measure_outputs():
n_subjects = 10
n_features = 49
# Generate signals and compute covariances
emp_covs = []
ledoit_covs = []
signals = []
ledoit_estimator = LedoitWolf()
for k in range(n_subjects):
n_samples = 200 + k
signal, _, _ = generate_signals(n_features=n_features, n_confounds=5,
length=n_samples, same_variance=False)
signals.append(signal)
signal -= signal.mean(axis=0)
emp_covs.append((signal.T).dot(signal) / n_samples)
ledoit_covs.append(ledoit_estimator.fit(signal).covariance_)
kinds = ["covariance", "correlation", "tangent", "precision",
"partial correlation"]
# Check outputs properties
for cov_estimator, covs in zip([EmpiricalCovariance(), LedoitWolf()],
[emp_covs, ledoit_covs]):
input_covs = copy.copy(covs)
for kind in kinds:
conn_measure = ConnectivityMeasure(kind=kind,
cov_estimator=cov_estimator)
connectivities = conn_measure.fit_transform(signals)
# Generic
assert_true(isinstance(connectivities, np.ndarray))
assert_equal(len(connectivities), len(covs))
for k, cov_new in enumerate(connectivities):
assert_array_equal(input_covs[k], covs[k])
assert(is_spd(covs[k], decimal=7))
# Positive definiteness if expected and output value checks
if kind == "tangent":
assert_array_almost_equal(cov_new, cov_new.T)
gmean_sqrt = _map_eigenvalues(np.sqrt,
conn_measure.mean_)
assert(is_spd(gmean_sqrt, decimal=7))
assert(is_spd(conn_measure.whitening_, decimal=7))
assert_array_almost_equal(conn_measure.whitening_.dot(
gmean_sqrt), np.eye(n_features))
assert_array_almost_equal(gmean_sqrt.dot(
_map_eigenvalues(np.exp, cov_new)).dot(gmean_sqrt),
covs[k])
elif kind == "precision":
assert(is_spd(cov_new, decimal=7))
assert_array_almost_equal(cov_new.dot(covs[k]),
np.eye(n_features))
elif kind == "correlation":
assert(is_spd(cov_new, decimal=7))
d = np.sqrt(np.diag(np.diag(covs[k])))
if cov_estimator == EmpiricalCovariance():
assert_array_almost_equal(d.dot(cov_new).dot(d),
covs[k])
assert_array_almost_equal(np.diag(cov_new),
np.ones((n_features)))
elif kind == "partial correlation":
prec = linalg.inv(covs[k])
d = np.sqrt(np.diag(np.diag(prec)))
assert_array_almost_equal(d.dot(cov_new).dot(d), -prec +
2 * np.diag(np.diag(prec)))
# Check the mean_
for kind in kinds:
conn_measure = ConnectivityMeasure(kind=kind)
conn_measure.fit_transform(signals)
assert_equal((conn_measure.mean_).shape, (n_features, n_features))
if kind != 'tangent':
assert_array_almost_equal(
conn_measure.mean_,
np.mean(conn_measure.transform(signals), axis=0))
# Check that the mean isn't modified in transform
conn_measure = ConnectivityMeasure(kind='covariance')
conn_measure.fit(signals[:1])
mean = conn_measure.mean_
conn_measure.transform(signals[1:])
assert_array_equal(mean, conn_measure.mean_)
# Check vectorization option
for kind in kinds:
conn_measure = ConnectivityMeasure(kind=kind)
connectivities = conn_measure.fit_transform(signals)
conn_measure = ConnectivityMeasure(vectorize=True, kind=kind)
vectorized_connectivities = conn_measure.fit_transform(signals)
assert_array_almost_equal(vectorized_connectivities,
sym_matrix_to_vec(connectivities))
# Check not fitted error
assert_raises_regex(
ValueError, 'has not been fitted. ',
ConnectivityMeasure().inverse_transform,
vectorized_connectivities)
# Check inverse transformation
kinds.remove('tangent')
for kind in kinds:
# without vectorization: input matrices are returned with no change
conn_measure = ConnectivityMeasure(kind=kind)
connectivities = conn_measure.fit_transform(signals)
assert_array_almost_equal(
conn_measure.inverse_transform(connectivities), connectivities)
# with vectorization: input vectors are reshaped into matrices
# if diagonal has not been discarded
conn_measure = ConnectivityMeasure(kind=kind, vectorize=True)
vectorized_connectivities = conn_measure.fit_transform(signals)
assert_array_almost_equal(
conn_measure.inverse_transform(vectorized_connectivities),
connectivities)
# with vectorization if diagonal has been discarded
for kind in ['correlation', 'partial correlation']:
connectivities = ConnectivityMeasure(kind=kind).fit_transform(signals)
conn_measure = ConnectivityMeasure(kind=kind, vectorize=True,
discard_diagonal=True)
vectorized_connectivities = conn_measure.fit_transform(signals)
assert_array_almost_equal(
conn_measure.inverse_transform(vectorized_connectivities),
connectivities)
for kind in ['covariance', 'precision']:
connectivities = ConnectivityMeasure(kind=kind).fit_transform(signals)
conn_measure = ConnectivityMeasure(kind=kind, vectorize=True,
discard_diagonal=True)
vectorized_connectivities = conn_measure.fit_transform(signals)
diagonal = np.array([np.diagonal(conn) / sqrt(2) for conn in
connectivities])
inverse_transformed = conn_measure.inverse_transform(
vectorized_connectivities, diagonal=diagonal)
assert_array_almost_equal(inverse_transformed, connectivities)
assert_raises_regex(ValueError,
'can not reconstruct connectivity matrices',
conn_measure.inverse_transform,
vectorized_connectivities)
# for 'tangent' kind, covariance matrices are reconstructed
# without vectorization
tangent_measure = ConnectivityMeasure(kind='tangent')
displacements = tangent_measure.fit_transform(signals)
covariances = ConnectivityMeasure(kind='covariance').fit_transform(
signals)
assert_array_almost_equal(
tangent_measure.inverse_transform(displacements), covariances)
# with vectorization
# when diagonal has not been discarded
tangent_measure = ConnectivityMeasure(kind='tangent', vectorize=True)
vectorized_displacements = tangent_measure.fit_transform(signals)
assert_array_almost_equal(
tangent_measure.inverse_transform(vectorized_displacements),
covariances)
# when diagonal has been discarded
tangent_measure = ConnectivityMeasure(kind='tangent', vectorize=True,
discard_diagonal=True)
vectorized_displacements = tangent_measure.fit_transform(signals)
diagonal = np.array([np.diagonal(matrix) / sqrt(2) for matrix in
displacements])
inverse_transformed = tangent_measure.inverse_transform(
vectorized_displacements, diagonal=diagonal)
assert_array_almost_equal(inverse_transformed, covariances)
assert_raises_regex(ValueError,
'can not reconstruct connectivity matrices',
tangent_measure.inverse_transform,
vectorized_displacements)
def test_connectivity_measure_outputs():
n_subjects = 10
n_features = 49
# Generate signals and compute covariances
emp_covs = []
ledoit_covs = []
signals = []
ledoit_estimator = LedoitWolf()
for k in range(n_subjects):
n_samples = 200 + k
signal, _, _ = generate_signals(n_features=n_features, n_confounds=5,
length=n_samples, same_variance=False)
signals.append(signal)
signal -= signal.mean(axis=0)
emp_covs.append((signal.T).dot(signal) / n_samples)
ledoit_covs.append(ledoit_estimator.fit(signal).covariance_)
kinds = ["covariance", "correlation", "tangent", "precision",
"partial correlation"]
# Check outputs properties
for cov_estimator, covs in zip([EmpiricalCovariance(), LedoitWolf()],
[emp_covs, ledoit_covs]):
input_covs = copy.copy(covs)
for kind in kinds:
conn_measure = ConnectivityMeasure(kind=kind,
cov_estimator=cov_estimator)
connectivities = conn_measure.fit_transform(signals)
# Generic
assert isinstance(connectivities, np.ndarray)
assert len(connectivities) == len(covs)
for k, cov_new in enumerate(connectivities):
assert_array_equal(input_covs[k], covs[k])
assert(is_spd(covs[k], decimal=7))
# Positive definiteness if expected and output value checks
if kind == "tangent":
assert_array_almost_equal(cov_new, cov_new.T)
gmean_sqrt = _map_eigenvalues(np.sqrt,
conn_measure.mean_)
assert(is_spd(gmean_sqrt, decimal=7))
assert(is_spd(conn_measure.whitening_, decimal=7))
assert_array_almost_equal(conn_measure.whitening_.dot(
gmean_sqrt), np.eye(n_features))
assert_array_almost_equal(gmean_sqrt.dot(
_map_eigenvalues(np.exp, cov_new)).dot(gmean_sqrt),
covs[k])
elif kind == "precision":
assert(is_spd(cov_new, decimal=7))
assert_array_almost_equal(cov_new.dot(covs[k]),
np.eye(n_features))
elif kind == "correlation":
assert(is_spd(cov_new, decimal=7))
d = np.sqrt(np.diag(np.diag(covs[k])))
if cov_estimator == EmpiricalCovariance():
assert_array_almost_equal(d.dot(cov_new).dot(d),
covs[k])
assert_array_almost_equal(np.diag(cov_new),
np.ones((n_features)))
elif kind == "partial correlation":
prec = linalg.inv(covs[k])
d = np.sqrt(np.diag(np.diag(prec)))
assert_array_almost_equal(d.dot(cov_new).dot(d), -prec +
2 * np.diag(np.diag(prec)))
# Check the mean_
for kind in kinds:
conn_measure = ConnectivityMeasure(kind=kind)
conn_measure.fit_transform(signals)
assert (conn_measure.mean_).shape == (n_features, n_features)
if kind != 'tangent':
assert_array_almost_equal(
conn_measure.mean_,
np.mean(conn_measure.transform(signals), axis=0))
# Check that the mean isn't modified in transform
conn_measure = ConnectivityMeasure(kind='covariance')
conn_measure.fit(signals[:1])
mean = conn_measure.mean_
conn_measure.transform(signals[1:])
assert_array_equal(mean, conn_measure.mean_)
# Check vectorization option
for kind in kinds:
conn_measure = ConnectivityMeasure(kind=kind)
connectivities = conn_measure.fit_transform(signals)
conn_measure = ConnectivityMeasure(vectorize=True, kind=kind)
vectorized_connectivities = conn_measure.fit_transform(signals)
assert_array_almost_equal(vectorized_connectivities,
sym_matrix_to_vec(connectivities))
# Check not fitted error
with pytest.raises(ValueError, match='has not been fitted. '):
ConnectivityMeasure().inverse_transform(vectorized_connectivities)
# Check inverse transformation
kinds.remove('tangent')
for kind in kinds:
# without vectorization: input matrices are returned with no change
conn_measure = ConnectivityMeasure(kind=kind)
connectivities = conn_measure.fit_transform(signals)
assert_array_almost_equal(
conn_measure.inverse_transform(connectivities), connectivities)
# with vectorization: input vectors are reshaped into matrices
# if diagonal has not been discarded
conn_measure = ConnectivityMeasure(kind=kind, vectorize=True)
vectorized_connectivities = conn_measure.fit_transform(signals)
assert_array_almost_equal(
conn_measure.inverse_transform(vectorized_connectivities),
connectivities)
# with vectorization if diagonal has been discarded
for kind in ['correlation', 'partial correlation']:
connectivities = ConnectivityMeasure(kind=kind).fit_transform(signals)
conn_measure = ConnectivityMeasure(kind=kind, vectorize=True,
discard_diagonal=True)
vectorized_connectivities = conn_measure.fit_transform(signals)
assert_array_almost_equal(
conn_measure.inverse_transform(vectorized_connectivities),
connectivities)
for kind in ['covariance', 'precision']:
connectivities = ConnectivityMeasure(kind=kind).fit_transform(signals)
conn_measure = ConnectivityMeasure(kind=kind, vectorize=True,
discard_diagonal=True)
vectorized_connectivities = conn_measure.fit_transform(signals)
diagonal = np.array([np.diagonal(conn) / sqrt(2) for conn in
connectivities])
inverse_transformed = conn_measure.inverse_transform(
vectorized_connectivities, diagonal=diagonal)
assert_array_almost_equal(inverse_transformed, connectivities)
with pytest.raises(ValueError,
match='can not reconstruct connectivity matrices'):
conn_measure.inverse_transform(vectorized_connectivities)
# for 'tangent' kind, covariance matrices are reconstructed
# without vectorization
tangent_measure = ConnectivityMeasure(kind='tangent')
displacements = tangent_measure.fit_transform(signals)
covariances = ConnectivityMeasure(kind='covariance').fit_transform(
signals)
assert_array_almost_equal(
tangent_measure.inverse_transform(displacements), covariances)
# with vectorization
# when diagonal has not been discarded
tangent_measure = ConnectivityMeasure(kind='tangent', vectorize=True)
vectorized_displacements = tangent_measure.fit_transform(signals)
assert_array_almost_equal(
tangent_measure.inverse_transform(vectorized_displacements),
covariances)
# when diagonal has been discarded
tangent_measure = ConnectivityMeasure(kind='tangent', vectorize=True,
discard_diagonal=True)
vectorized_displacements = tangent_measure.fit_transform(signals)
diagonal = np.array([np.diagonal(matrix) / sqrt(2) for matrix in
displacements])
inverse_transformed = tangent_measure.inverse_transform(
vectorized_displacements, diagonal=diagonal)
assert_array_almost_equal(inverse_transformed, covariances)
with pytest.raises(ValueError,
match='can not reconstruct connectivity matrices'):
tangent_measure.inverse_transform(vectorized_displacements)