projektAI/venv/Lib/site-packages/sklearn/decomposition/tests/test_nmf.py

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2021-06-06 22:13:05 +02:00
import numpy as np
import scipy.sparse as sp
from scipy import linalg
from sklearn.decomposition import NMF, non_negative_factorization
from sklearn.decomposition import _nmf as nmf # For testing internals
from scipy.sparse import csc_matrix
import pytest
from sklearn.utils._testing import assert_raise_message
from sklearn.utils._testing import assert_array_equal
from sklearn.utils._testing import assert_array_almost_equal
from sklearn.utils._testing import assert_almost_equal
from sklearn.utils._testing import assert_allclose
from sklearn.utils._testing import ignore_warnings
from sklearn.utils.extmath import squared_norm
from sklearn.base import clone
from sklearn.exceptions import ConvergenceWarning
@pytest.mark.parametrize('solver', ['cd', 'mu'])
@pytest.mark.parametrize('regularization',
[None, 'both', 'components', 'transformation'])
def test_convergence_warning(solver, regularization):
convergence_warning = ("Maximum number of iterations 1 reached. "
"Increase it to improve convergence.")
A = np.ones((2, 2))
with pytest.warns(ConvergenceWarning, match=convergence_warning):
NMF(solver=solver, regularization=regularization, max_iter=1).fit(A)
def test_initialize_nn_output():
# Test that initialization does not return negative values
rng = np.random.mtrand.RandomState(42)
data = np.abs(rng.randn(10, 10))
for init in ('random', 'nndsvd', 'nndsvda', 'nndsvdar'):
W, H = nmf._initialize_nmf(data, 10, init=init, random_state=0)
assert not ((W < 0).any() or (H < 0).any())
def test_parameter_checking():
A = np.ones((2, 2))
name = 'spam'
# FIXME : should be removed in 1.1
init = 'nndsvda'
msg = "Invalid solver parameter: got 'spam' instead of one of"
assert_raise_message(ValueError, msg, NMF(solver=name, init=init).fit, A)
msg = "Invalid init parameter: got 'spam' instead of one of"
assert_raise_message(ValueError, msg, NMF(init=name).fit, A)
msg = "Invalid regularization parameter: got 'spam' instead of one of"
assert_raise_message(ValueError, msg, NMF(regularization=name,
init=init).fit, A)
msg = "Invalid beta_loss parameter: got 'spam' instead of one"
assert_raise_message(ValueError, msg, NMF(solver='mu', init=init,
beta_loss=name).fit, A)
msg = "Invalid beta_loss parameter: solver 'cd' does not handle "
msg += "beta_loss = 1.0"
assert_raise_message(ValueError, msg, NMF(solver='cd', init=init,
beta_loss=1.0).fit, A)
msg = "Negative values in data passed to"
assert_raise_message(ValueError, msg, NMF(init=init).fit, -A)
assert_raise_message(ValueError, msg, nmf._initialize_nmf, -A,
2, 'nndsvd')
clf = NMF(2, tol=0.1, init=init).fit(A)
assert_raise_message(ValueError, msg, clf.transform, -A)
for init in ['nndsvd', 'nndsvda', 'nndsvdar']:
msg = ("init = '{}' can only be used when "
"n_components <= min(n_samples, n_features)"
.format(init))
assert_raise_message(ValueError, msg, NMF(3, init=init).fit, A)
assert_raise_message(ValueError, msg, nmf._initialize_nmf, A,
3, init)
def test_initialize_close():
# Test NNDSVD error
# Test that _initialize_nmf error is less than the standard deviation of
# the entries in the matrix.
rng = np.random.mtrand.RandomState(42)
A = np.abs(rng.randn(10, 10))
W, H = nmf._initialize_nmf(A, 10, init='nndsvd')
error = linalg.norm(np.dot(W, H) - A)
sdev = linalg.norm(A - A.mean())
assert error <= sdev
def test_initialize_variants():
# Test NNDSVD variants correctness
# Test that the variants 'nndsvda' and 'nndsvdar' differ from basic
# 'nndsvd' only where the basic version has zeros.
rng = np.random.mtrand.RandomState(42)
data = np.abs(rng.randn(10, 10))
W0, H0 = nmf._initialize_nmf(data, 10, init='nndsvd')
Wa, Ha = nmf._initialize_nmf(data, 10, init='nndsvda')
War, Har = nmf._initialize_nmf(data, 10, init='nndsvdar',
random_state=0)
for ref, evl in ((W0, Wa), (W0, War), (H0, Ha), (H0, Har)):
assert_almost_equal(evl[ref != 0], ref[ref != 0])
# ignore UserWarning raised when both solver='mu' and init='nndsvd'
@ignore_warnings(category=UserWarning)
@pytest.mark.parametrize('solver', ('cd', 'mu'))
@pytest.mark.parametrize('init',
(None, 'nndsvd', 'nndsvda', 'nndsvdar', 'random'))
@pytest.mark.parametrize('regularization',
(None, 'both', 'components', 'transformation'))
def test_nmf_fit_nn_output(solver, init, regularization):
# Test that the decomposition does not contain negative values
A = np.c_[5. - np.arange(1, 6),
5. + np.arange(1, 6)]
model = NMF(n_components=2, solver=solver, init=init,
regularization=regularization, random_state=0)
transf = model.fit_transform(A)
assert not((model.components_ < 0).any() or
(transf < 0).any())
@pytest.mark.parametrize('solver', ('cd', 'mu'))
@pytest.mark.parametrize('regularization',
(None, 'both', 'components', 'transformation'))
def test_nmf_fit_close(solver, regularization):
rng = np.random.mtrand.RandomState(42)
# Test that the fit is not too far away
pnmf = NMF(5, solver=solver, init='nndsvdar', random_state=0,
regularization=regularization, max_iter=600)
X = np.abs(rng.randn(6, 5))
assert pnmf.fit(X).reconstruction_err_ < 0.1
@pytest.mark.parametrize('solver', ('cd', 'mu'))
@pytest.mark.parametrize('regularization',
(None, 'both', 'components', 'transformation'))
def test_nmf_transform(solver, regularization):
# Test that NMF.transform returns close values
rng = np.random.mtrand.RandomState(42)
A = np.abs(rng.randn(6, 5))
m = NMF(solver=solver, n_components=3, init='random',
regularization=regularization, random_state=0, tol=1e-5)
ft = m.fit_transform(A)
t = m.transform(A)
assert_array_almost_equal(ft, t, decimal=2)
def test_nmf_transform_custom_init():
# Smoke test that checks if NMF.transform works with custom initialization
random_state = np.random.RandomState(0)
A = np.abs(random_state.randn(6, 5))
n_components = 4
avg = np.sqrt(A.mean() / n_components)
H_init = np.abs(avg * random_state.randn(n_components, 5))
W_init = np.abs(avg * random_state.randn(6, n_components))
m = NMF(solver='cd', n_components=n_components, init='custom',
random_state=0)
m.fit_transform(A, W=W_init, H=H_init)
m.transform(A)
@pytest.mark.parametrize('solver', ('cd', 'mu'))
@pytest.mark.parametrize('regularization',
(None, 'both', 'components', 'transformation'))
def test_nmf_inverse_transform(solver, regularization):
# Test that NMF.inverse_transform returns close values
random_state = np.random.RandomState(0)
A = np.abs(random_state.randn(6, 4))
m = NMF(solver=solver, n_components=4, init='random', random_state=0,
regularization=regularization, max_iter=1000)
ft = m.fit_transform(A)
A_new = m.inverse_transform(ft)
assert_array_almost_equal(A, A_new, decimal=2)
def test_n_components_greater_n_features():
# Smoke test for the case of more components than features.
rng = np.random.mtrand.RandomState(42)
A = np.abs(rng.randn(30, 10))
# FIXME : should be removed in 1.1
init = 'random'
NMF(n_components=15, random_state=0, tol=1e-2, init=init).fit(A)
@pytest.mark.parametrize('solver', ['cd', 'mu'])
@pytest.mark.parametrize('regularization',
[None, 'both', 'components', 'transformation'])
def test_nmf_sparse_input(solver, regularization):
# Test that sparse matrices are accepted as input
from scipy.sparse import csc_matrix
rng = np.random.mtrand.RandomState(42)
A = np.abs(rng.randn(10, 10))
A[:, 2 * np.arange(5)] = 0
A_sparse = csc_matrix(A)
est1 = NMF(solver=solver, n_components=5, init='random',
regularization=regularization, random_state=0,
tol=1e-2)
est2 = clone(est1)
W1 = est1.fit_transform(A)
W2 = est2.fit_transform(A_sparse)
H1 = est1.components_
H2 = est2.components_
assert_array_almost_equal(W1, W2)
assert_array_almost_equal(H1, H2)
def test_nmf_sparse_transform():
# Test that transform works on sparse data. Issue #2124
rng = np.random.mtrand.RandomState(42)
A = np.abs(rng.randn(3, 2))
A[1, 1] = 0
A = csc_matrix(A)
for solver in ('cd', 'mu'):
model = NMF(solver=solver, random_state=0, n_components=2,
max_iter=400, init='nndsvd')
A_fit_tr = model.fit_transform(A)
A_tr = model.transform(A)
assert_array_almost_equal(A_fit_tr, A_tr, decimal=1)
@pytest.mark.parametrize('init', ['random', 'nndsvd'])
@pytest.mark.parametrize('solver', ('cd', 'mu'))
@pytest.mark.parametrize('regularization',
(None, 'both', 'components', 'transformation'))
def test_non_negative_factorization_consistency(init, solver, regularization):
# Test that the function is called in the same way, either directly
# or through the NMF class
rng = np.random.mtrand.RandomState(42)
A = np.abs(rng.randn(10, 10))
A[:, 2 * np.arange(5)] = 0
W_nmf, H, _ = non_negative_factorization(
A, init=init, solver=solver,
regularization=regularization, random_state=1, tol=1e-2)
W_nmf_2, _, _ = non_negative_factorization(
A, H=H, update_H=False, init=init, solver=solver,
regularization=regularization, random_state=1, tol=1e-2)
model_class = NMF(init=init, solver=solver,
regularization=regularization,
random_state=1, tol=1e-2)
W_cls = model_class.fit_transform(A)
W_cls_2 = model_class.transform(A)
assert_array_almost_equal(W_nmf, W_cls, decimal=10)
assert_array_almost_equal(W_nmf_2, W_cls_2, decimal=10)
def test_non_negative_factorization_checking():
A = np.ones((2, 2))
# Test parameters checking is public function
nnmf = non_negative_factorization
msg = ("Number of components must be a positive integer; "
"got (n_components=1.5)")
assert_raise_message(ValueError, msg, nnmf, A, A, A, 1.5, init='random')
msg = ("Number of components must be a positive integer; "
"got (n_components='2')")
assert_raise_message(ValueError, msg, nnmf, A, A, A, '2', init='random')
msg = "Negative values in data passed to NMF (input H)"
assert_raise_message(ValueError, msg, nnmf, A, A, -A, 2, init='custom')
msg = "Negative values in data passed to NMF (input W)"
assert_raise_message(ValueError, msg, nnmf, A, -A, A, 2, init='custom')
msg = "Array passed to NMF (input H) is full of zeros"
assert_raise_message(ValueError, msg, nnmf, A, A, 0 * A, 2, init='custom')
msg = "Invalid regularization parameter: got 'spam' instead of one of"
assert_raise_message(ValueError, msg, nnmf, A, A, 0 * A, 2, init='custom',
regularization='spam')
def _beta_divergence_dense(X, W, H, beta):
"""Compute the beta-divergence of X and W.H for dense array only.
Used as a reference for testing nmf._beta_divergence.
"""
WH = np.dot(W, H)
if beta == 2:
return squared_norm(X - WH) / 2
WH_Xnonzero = WH[X != 0]
X_nonzero = X[X != 0]
np.maximum(WH_Xnonzero, 1e-9, out=WH_Xnonzero)
if beta == 1:
res = np.sum(X_nonzero * np.log(X_nonzero / WH_Xnonzero))
res += WH.sum() - X.sum()
elif beta == 0:
div = X_nonzero / WH_Xnonzero
res = np.sum(div) - X.size - np.sum(np.log(div))
else:
res = (X_nonzero ** beta).sum()
res += (beta - 1) * (WH ** beta).sum()
res -= beta * (X_nonzero * (WH_Xnonzero ** (beta - 1))).sum()
res /= beta * (beta - 1)
return res
def test_beta_divergence():
# Compare _beta_divergence with the reference _beta_divergence_dense
n_samples = 20
n_features = 10
n_components = 5
beta_losses = [0., 0.5, 1., 1.5, 2.]
# initialization
rng = np.random.mtrand.RandomState(42)
X = rng.randn(n_samples, n_features)
np.clip(X, 0, None, out=X)
X_csr = sp.csr_matrix(X)
W, H = nmf._initialize_nmf(X, n_components, init='random', random_state=42)
for beta in beta_losses:
ref = _beta_divergence_dense(X, W, H, beta)
loss = nmf._beta_divergence(X, W, H, beta)
loss_csr = nmf._beta_divergence(X_csr, W, H, beta)
assert_almost_equal(ref, loss, decimal=7)
assert_almost_equal(ref, loss_csr, decimal=7)
def test_special_sparse_dot():
# Test the function that computes np.dot(W, H), only where X is non zero.
n_samples = 10
n_features = 5
n_components = 3
rng = np.random.mtrand.RandomState(42)
X = rng.randn(n_samples, n_features)
np.clip(X, 0, None, out=X)
X_csr = sp.csr_matrix(X)
W = np.abs(rng.randn(n_samples, n_components))
H = np.abs(rng.randn(n_components, n_features))
WH_safe = nmf._special_sparse_dot(W, H, X_csr)
WH = nmf._special_sparse_dot(W, H, X)
# test that both results have same values, in X_csr nonzero elements
ii, jj = X_csr.nonzero()
WH_safe_data = np.asarray(WH_safe[ii, jj]).ravel()
assert_array_almost_equal(WH_safe_data, WH[ii, jj], decimal=10)
# test that WH_safe and X_csr have the same sparse structure
assert_array_equal(WH_safe.indices, X_csr.indices)
assert_array_equal(WH_safe.indptr, X_csr.indptr)
assert_array_equal(WH_safe.shape, X_csr.shape)
@ignore_warnings(category=ConvergenceWarning)
def test_nmf_multiplicative_update_sparse():
# Compare sparse and dense input in multiplicative update NMF
# Also test continuity of the results with respect to beta_loss parameter
n_samples = 20
n_features = 10
n_components = 5
alpha = 0.1
l1_ratio = 0.5
n_iter = 20
# initialization
rng = np.random.mtrand.RandomState(1337)
X = rng.randn(n_samples, n_features)
X = np.abs(X)
X_csr = sp.csr_matrix(X)
W0, H0 = nmf._initialize_nmf(X, n_components, init='random',
random_state=42)
for beta_loss in (-1.2, 0, 0.2, 1., 2., 2.5):
# Reference with dense array X
W, H = W0.copy(), H0.copy()
W1, H1, _ = non_negative_factorization(
X, W, H, n_components, init='custom', update_H=True,
solver='mu', beta_loss=beta_loss, max_iter=n_iter, alpha=alpha,
l1_ratio=l1_ratio, regularization='both', random_state=42)
# Compare with sparse X
W, H = W0.copy(), H0.copy()
W2, H2, _ = non_negative_factorization(
X_csr, W, H, n_components, init='custom', update_H=True,
solver='mu', beta_loss=beta_loss, max_iter=n_iter, alpha=alpha,
l1_ratio=l1_ratio, regularization='both', random_state=42)
assert_array_almost_equal(W1, W2, decimal=7)
assert_array_almost_equal(H1, H2, decimal=7)
# Compare with almost same beta_loss, since some values have a specific
# behavior, but the results should be continuous w.r.t beta_loss
beta_loss -= 1.e-5
W, H = W0.copy(), H0.copy()
W3, H3, _ = non_negative_factorization(
X_csr, W, H, n_components, init='custom', update_H=True,
solver='mu', beta_loss=beta_loss, max_iter=n_iter, alpha=alpha,
l1_ratio=l1_ratio, regularization='both', random_state=42)
assert_array_almost_equal(W1, W3, decimal=4)
assert_array_almost_equal(H1, H3, decimal=4)
def test_nmf_negative_beta_loss():
# Test that an error is raised if beta_loss < 0 and X contains zeros.
# Test that the output has not NaN values when the input contains zeros.
n_samples = 6
n_features = 5
n_components = 3
rng = np.random.mtrand.RandomState(42)
X = rng.randn(n_samples, n_features)
np.clip(X, 0, None, out=X)
X_csr = sp.csr_matrix(X)
def _assert_nmf_no_nan(X, beta_loss):
W, H, _ = non_negative_factorization(
X, init='random', n_components=n_components, solver='mu',
beta_loss=beta_loss, random_state=0, max_iter=1000)
assert not np.any(np.isnan(W))
assert not np.any(np.isnan(H))
msg = "When beta_loss <= 0 and X contains zeros, the solver may diverge."
for beta_loss in (-0.6, 0.):
assert_raise_message(ValueError, msg, _assert_nmf_no_nan, X, beta_loss)
_assert_nmf_no_nan(X + 1e-9, beta_loss)
for beta_loss in (0.2, 1., 1.2, 2., 2.5):
_assert_nmf_no_nan(X, beta_loss)
_assert_nmf_no_nan(X_csr, beta_loss)
def test_nmf_regularization():
# Test the effect of L1 and L2 regularizations
n_samples = 6
n_features = 5
n_components = 3
rng = np.random.mtrand.RandomState(42)
X = np.abs(rng.randn(n_samples, n_features))
# FIXME : should be removed in 1.1
init = 'nndsvda'
# L1 regularization should increase the number of zeros
l1_ratio = 1.
for solver in ['cd', 'mu']:
regul = nmf.NMF(n_components=n_components, solver=solver,
alpha=0.5, l1_ratio=l1_ratio, random_state=42,
init=init)
model = nmf.NMF(n_components=n_components, solver=solver,
alpha=0., l1_ratio=l1_ratio, random_state=42,
init=init)
W_regul = regul.fit_transform(X)
W_model = model.fit_transform(X)
H_regul = regul.components_
H_model = model.components_
W_regul_n_zeros = W_regul[W_regul == 0].size
W_model_n_zeros = W_model[W_model == 0].size
H_regul_n_zeros = H_regul[H_regul == 0].size
H_model_n_zeros = H_model[H_model == 0].size
assert W_regul_n_zeros > W_model_n_zeros
assert H_regul_n_zeros > H_model_n_zeros
# L2 regularization should decrease the mean of the coefficients
l1_ratio = 0.
for solver in ['cd', 'mu']:
regul = nmf.NMF(n_components=n_components, solver=solver,
alpha=0.5, l1_ratio=l1_ratio, random_state=42,
init=init)
model = nmf.NMF(n_components=n_components, solver=solver,
alpha=0., l1_ratio=l1_ratio, random_state=42,
init=init)
W_regul = regul.fit_transform(X)
W_model = model.fit_transform(X)
H_regul = regul.components_
H_model = model.components_
assert (linalg.norm(W_model))**2. + (linalg.norm(H_model))**2. > \
(linalg.norm(W_regul))**2. + (linalg.norm(H_regul))**2.
@ignore_warnings(category=ConvergenceWarning)
def test_nmf_decreasing():
# test that the objective function is decreasing at each iteration
n_samples = 20
n_features = 15
n_components = 10
alpha = 0.1
l1_ratio = 0.5
tol = 0.
# initialization
rng = np.random.mtrand.RandomState(42)
X = rng.randn(n_samples, n_features)
np.abs(X, X)
W0, H0 = nmf._initialize_nmf(X, n_components, init='random',
random_state=42)
for beta_loss in (-1.2, 0, 0.2, 1., 2., 2.5):
for solver in ('cd', 'mu'):
if solver != 'mu' and beta_loss != 2:
# not implemented
continue
W, H = W0.copy(), H0.copy()
previous_loss = None
for _ in range(30):
# one more iteration starting from the previous results
W, H, _ = non_negative_factorization(
X, W, H, beta_loss=beta_loss, init='custom',
n_components=n_components, max_iter=1, alpha=alpha,
solver=solver, tol=tol, l1_ratio=l1_ratio, verbose=0,
regularization='both', random_state=0, update_H=True)
loss = nmf._beta_divergence(X, W, H, beta_loss)
if previous_loss is not None:
assert previous_loss > loss
previous_loss = loss
def test_nmf_underflow():
# Regression test for an underflow issue in _beta_divergence
rng = np.random.RandomState(0)
n_samples, n_features, n_components = 10, 2, 2
X = np.abs(rng.randn(n_samples, n_features)) * 10
W = np.abs(rng.randn(n_samples, n_components)) * 10
H = np.abs(rng.randn(n_components, n_features))
X[0, 0] = 0
ref = nmf._beta_divergence(X, W, H, beta=1.0)
X[0, 0] = 1e-323
res = nmf._beta_divergence(X, W, H, beta=1.0)
assert_almost_equal(res, ref)
@pytest.mark.parametrize("dtype_in, dtype_out", [
(np.float32, np.float32),
(np.float64, np.float64),
(np.int32, np.float64),
(np.int64, np.float64)])
@pytest.mark.parametrize("solver", ["cd", "mu"])
@pytest.mark.parametrize("regularization",
(None, "both", "components", "transformation"))
def test_nmf_dtype_match(dtype_in, dtype_out, solver, regularization):
# Check that NMF preserves dtype (float32 and float64)
X = np.random.RandomState(0).randn(20, 15).astype(dtype_in, copy=False)
np.abs(X, out=X)
# FIXME : should be removed in 1.1
init = 'nndsvda'
nmf = NMF(solver=solver, regularization=regularization, init=init)
assert nmf.fit(X).transform(X).dtype == dtype_out
assert nmf.fit_transform(X).dtype == dtype_out
assert nmf.components_.dtype == dtype_out
@pytest.mark.parametrize("solver", ["cd", "mu"])
@pytest.mark.parametrize("regularization",
(None, "both", "components", "transformation"))
def test_nmf_float32_float64_consistency(solver, regularization):
# Check that the result of NMF is the same between float32 and float64
X = np.random.RandomState(0).randn(50, 7)
np.abs(X, out=X)
# FIXME : should be removed in 1.1
init = 'nndsvda'
nmf32 = NMF(solver=solver, regularization=regularization, random_state=0,
init=init)
W32 = nmf32.fit_transform(X.astype(np.float32))
nmf64 = NMF(solver=solver, regularization=regularization, random_state=0,
init=init)
W64 = nmf64.fit_transform(X)
assert_allclose(W32, W64, rtol=1e-6, atol=1e-5)
def test_nmf_custom_init_dtype_error():
# Check that an error is raise if custom H and/or W don't have the same
# dtype as X.
rng = np.random.RandomState(0)
X = rng.random_sample((20, 15))
H = rng.random_sample((15, 15)).astype(np.float32)
W = rng.random_sample((20, 15))
with pytest.raises(TypeError, match="should have the same dtype as X"):
NMF(init='custom').fit(X, H=H, W=W)
with pytest.raises(TypeError, match="should have the same dtype as X"):
non_negative_factorization(X, H=H, update_H=False)
# FIXME : should be removed in 1.1
def test_init_default_deprecation():
# Test FutureWarning on init default
msg = (r"The 'init' value, when 'init=None' and "
r"n_components is less than n_samples and "
r"n_features, will be changed from 'nndsvd' to "
r"'nndsvda' in 1.1 \(renaming of 0.26\).")
rng = np.random.mtrand.RandomState(42)
A = np.abs(rng.randn(6, 5))
with pytest.warns(FutureWarning, match=msg):
nmf._initialize_nmf(A, 3)
with pytest.warns(FutureWarning, match=msg):
NMF().fit(A)
with pytest.warns(FutureWarning, match=msg):
non_negative_factorization(A)