scikit-learn/sklearn/decomposition/tests/test_nmf.py

180 lines
6.0 KiB
Python

import numpy as np
from scipy import linalg
from sklearn.decomposition import nmf
from sklearn.utils.testing import assert_true
from sklearn.utils.testing import assert_false
from sklearn.utils.testing import raises
from sklearn.utils.testing import assert_array_almost_equal
from sklearn.utils.testing import assert_greater
from sklearn.utils.testing import assert_less
random_state = np.random.mtrand.RandomState(0)
@raises(ValueError)
def test_initialize_nn_input():
"""Test NNDSVD behaviour on negative input"""
nmf._initialize_nmf(-np.ones((2, 2)), 2)
def test_initialize_nn_output():
"""Test that NNDSVD does not return negative values"""
data = np.abs(random_state.randn(10, 10))
for var in (None, 'a', 'ar'):
W, H = nmf._initialize_nmf(data, 10, random_state=0)
assert_false((W < 0).any() or (H < 0).any())
def test_initialize_close():
"""Test NNDSVD error
Test that _initialize_nmf error is less than the standard deviation of the
entries in the matrix.
"""
A = np.abs(random_state.randn(10, 10))
W, H = nmf._initialize_nmf(A, 10)
error = linalg.norm(np.dot(W, H) - A)
sdev = linalg.norm(A - A.mean())
assert_true(error <= sdev)
def test_initialize_variants():
"""Test NNDSVD variants correctness
Test that the variants 'a' and 'ar' differ from basic NNDSVD only where
the basic version has zeros.
"""
data = np.abs(random_state.randn(10, 10))
W0, H0 = nmf._initialize_nmf(data, 10, variant=None)
Wa, Ha = nmf._initialize_nmf(data, 10, variant='a')
War, Har = nmf._initialize_nmf(data, 10, variant='ar', random_state=0)
for ref, evl in ((W0, Wa), (W0, War), (H0, Ha), (H0, Har)):
assert_true(np.allclose(evl[ref != 0], ref[ref != 0]))
@raises(ValueError)
def test_projgrad_nmf_fit_nn_input():
"""Test model fit behaviour on negative input"""
A = -np.ones((2, 2))
m = nmf.ProjectedGradientNMF(n_components=2, init=None, random_state=0)
m.fit(A)
def test_projgrad_nmf_fit_nn_output():
"""Test that the decomposition does not contain negative values"""
A = np.c_[5 * np.ones(5) - np.arange(1, 6),
5 * np.ones(5) + np.arange(1, 6)]
for init in (None, 'nndsvd', 'nndsvda', 'nndsvdar'):
model = nmf.ProjectedGradientNMF(n_components=2, init=init,
random_state=0)
transf = model.fit_transform(A)
assert_false((model.components_ < 0).any() or
(transf < 0).any())
def test_projgrad_nmf_fit_close():
"""Test that the fit is not too far away"""
pnmf = nmf.ProjectedGradientNMF(5, init='nndsvda', random_state=0)
X = np.abs(random_state.randn(6, 5))
assert_less(pnmf.fit(X).reconstruction_err_, 0.05)
def test_nls_nn_output():
"""Test that NLS solver doesn't return negative values"""
A = np.arange(1, 5).reshape(1, -1)
Ap, _, _ = nmf._nls_subproblem(np.dot(A.T, -A), A.T, A, 0.001, 100)
assert_false((Ap < 0).any())
def test_nls_close():
"""Test that the NLS results should be close"""
A = np.arange(1, 5).reshape(1, -1)
Ap, _, _ = nmf._nls_subproblem(np.dot(A.T, A), A.T, np.zeros_like(A),
0.001, 100)
assert_true((np.abs(Ap - A) < 0.01).all())
def test_projgrad_nmf_transform():
"""Test that NMF.transform returns close values
(transform uses scipy.optimize.nnls for now)
"""
A = np.abs(random_state.randn(6, 5))
m = nmf.ProjectedGradientNMF(n_components=5, init='nndsvd', random_state=0)
transf = m.fit_transform(A)
assert_true(np.allclose(transf, m.transform(A), atol=1e-2, rtol=0))
def test_n_components_greater_n_features():
"""Smoke test for the case of more components than features."""
A = np.abs(random_state.randn(30, 10))
nmf.ProjectedGradientNMF(n_components=15, sparseness='data',
random_state=0).fit(A)
def test_projgrad_nmf_sparseness():
"""Test sparseness
Test that sparsity constraints actually increase sparseness in the
part where they are applied.
"""
A = np.abs(random_state.randn(10, 10))
m = nmf.ProjectedGradientNMF(n_components=5, random_state=0).fit(A)
data_sp = nmf.ProjectedGradientNMF(n_components=5, sparseness='data',
random_state=0).fit(A).data_sparseness_
comp_sp = nmf.ProjectedGradientNMF(n_components=5, sparseness='components',
random_state=0).fit(A).comp_sparseness_
assert_greater(data_sp, m.data_sparseness_)
assert_greater(comp_sp, m.comp_sparseness_)
def test_sparse_input():
"""Test that sparse matrices are accepted as input"""
from scipy.sparse import csc_matrix
A = np.abs(random_state.randn(10, 10))
A[:, 2 * np.arange(5)] = 0
T1 = nmf.ProjectedGradientNMF(n_components=5, init='random',
random_state=999).fit_transform(A)
A_sparse = csc_matrix(A)
pg_nmf = nmf.ProjectedGradientNMF(n_components=5, init='random',
random_state=999)
T2 = pg_nmf.fit_transform(A_sparse)
assert_array_almost_equal(pg_nmf.reconstruction_err_,
linalg.norm(A - np.dot(T2, pg_nmf.components_),
'fro'))
assert_array_almost_equal(T1, T2)
# same with sparseness
T2 = nmf.ProjectedGradientNMF(
n_components=5, init='random', sparseness='data',
random_state=999).fit_transform(A_sparse)
T1 = nmf.ProjectedGradientNMF(
n_components=5, init='random', sparseness='data',
random_state=999).fit_transform(A)
def test_sparse_transform():
"""Test that transform works on sparse data. Issue #2124"""
from scipy.sparse import csc_matrix
A = np.abs(random_state.randn(5, 4))
A[A > 1.0] = 0
A = csc_matrix(A)
model = nmf.NMF()
A_fit_tr = model.fit_transform(A)
A_tr = model.transform(A)
# This solver seems pretty inconsistent
assert_array_almost_equal(A_fit_tr, A_tr, decimal=2)
if __name__ == '__main__':
import nose
nose.run(argv=['', __file__])