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

249 lines
7.6 KiB
Python

import sys
import re
import pytest
import numpy as np
from scipy.sparse import csc_matrix, csr_matrix, lil_matrix
from sklearn.utils._testing import (
assert_almost_equal,
assert_array_equal,
assert_allclose,
)
from sklearn.datasets import load_digits
from io import StringIO
from sklearn.neural_network import BernoulliRBM
from sklearn.utils.validation import assert_all_finite
Xdigits, _ = load_digits(return_X_y=True)
Xdigits -= Xdigits.min()
Xdigits /= Xdigits.max()
def test_fit():
X = Xdigits.copy()
rbm = BernoulliRBM(
n_components=64, learning_rate=0.1, batch_size=10, n_iter=7, random_state=9
)
rbm.fit(X)
assert_almost_equal(rbm.score_samples(X).mean(), -21.0, decimal=0)
# in-place tricks shouldn't have modified X
assert_array_equal(X, Xdigits)
def test_partial_fit():
X = Xdigits.copy()
rbm = BernoulliRBM(
n_components=64, learning_rate=0.1, batch_size=20, random_state=9
)
n_samples = X.shape[0]
n_batches = int(np.ceil(float(n_samples) / rbm.batch_size))
batch_slices = np.array_split(X, n_batches)
for i in range(7):
for batch in batch_slices:
rbm.partial_fit(batch)
assert_almost_equal(rbm.score_samples(X).mean(), -21.0, decimal=0)
assert_array_equal(X, Xdigits)
def test_transform():
X = Xdigits[:100]
rbm1 = BernoulliRBM(n_components=16, batch_size=5, n_iter=5, random_state=42)
rbm1.fit(X)
Xt1 = rbm1.transform(X)
Xt2 = rbm1._mean_hiddens(X)
assert_array_equal(Xt1, Xt2)
def test_small_sparse():
# BernoulliRBM should work on small sparse matrices.
X = csr_matrix(Xdigits[:4])
BernoulliRBM().fit(X) # no exception
def test_small_sparse_partial_fit():
for sparse in [csc_matrix, csr_matrix]:
X_sparse = sparse(Xdigits[:100])
X = Xdigits[:100].copy()
rbm1 = BernoulliRBM(
n_components=64, learning_rate=0.1, batch_size=10, random_state=9
)
rbm2 = BernoulliRBM(
n_components=64, learning_rate=0.1, batch_size=10, random_state=9
)
rbm1.partial_fit(X_sparse)
rbm2.partial_fit(X)
assert_almost_equal(
rbm1.score_samples(X).mean(), rbm2.score_samples(X).mean(), decimal=0
)
def test_sample_hiddens():
rng = np.random.RandomState(0)
X = Xdigits[:100]
rbm1 = BernoulliRBM(n_components=2, batch_size=5, n_iter=5, random_state=42)
rbm1.fit(X)
h = rbm1._mean_hiddens(X[0])
hs = np.mean([rbm1._sample_hiddens(X[0], rng) for i in range(100)], 0)
assert_almost_equal(h, hs, decimal=1)
def test_fit_gibbs():
# XXX: this test is very seed-dependent! It probably needs to be rewritten.
# Gibbs on the RBM hidden layer should be able to recreate [[0], [1]]
# from the same input
rng = np.random.RandomState(42)
X = np.array([[0.0], [1.0]])
rbm1 = BernoulliRBM(n_components=2, batch_size=2, n_iter=42, random_state=rng)
# you need that much iters
rbm1.fit(X)
assert_almost_equal(
rbm1.components_, np.array([[0.02649814], [0.02009084]]), decimal=4
)
assert_almost_equal(rbm1.gibbs(X), X)
# Gibbs on the RBM hidden layer should be able to recreate [[0], [1]] from
# the same input even when the input is sparse, and test against non-sparse
rng = np.random.RandomState(42)
X = csc_matrix([[0.0], [1.0]])
rbm2 = BernoulliRBM(n_components=2, batch_size=2, n_iter=42, random_state=rng)
rbm2.fit(X)
assert_almost_equal(
rbm2.components_, np.array([[0.02649814], [0.02009084]]), decimal=4
)
assert_almost_equal(rbm2.gibbs(X), X.toarray())
assert_almost_equal(rbm1.components_, rbm2.components_)
def test_gibbs_smoke():
# Check if we don't get NaNs sampling the full digits dataset.
# Also check that sampling again will yield different results.
X = Xdigits
rbm1 = BernoulliRBM(n_components=42, batch_size=40, n_iter=20, random_state=42)
rbm1.fit(X)
X_sampled = rbm1.gibbs(X)
assert_all_finite(X_sampled)
X_sampled2 = rbm1.gibbs(X)
assert np.all((X_sampled != X_sampled2).max(axis=1))
def test_score_samples():
# Test score_samples (pseudo-likelihood) method.
# Assert that pseudo-likelihood is computed without clipping.
# See Fabian's blog, http://bit.ly/1iYefRk
rng = np.random.RandomState(42)
X = np.vstack([np.zeros(1000), np.ones(1000)])
rbm1 = BernoulliRBM(n_components=10, batch_size=2, n_iter=10, random_state=rng)
rbm1.fit(X)
assert (rbm1.score_samples(X) < -300).all()
# Sparse vs. dense should not affect the output. Also test sparse input
# validation.
rbm1.random_state = 42
d_score = rbm1.score_samples(X)
rbm1.random_state = 42
s_score = rbm1.score_samples(lil_matrix(X))
assert_almost_equal(d_score, s_score)
# Test numerical stability (#2785): would previously generate infinities
# and crash with an exception.
with np.errstate(under="ignore"):
rbm1.score_samples([np.arange(1000) * 100])
def test_rbm_verbose():
rbm = BernoulliRBM(n_iter=2, verbose=10)
old_stdout = sys.stdout
sys.stdout = StringIO()
try:
rbm.fit(Xdigits)
finally:
sys.stdout = old_stdout
def test_sparse_and_verbose():
# Make sure RBM works with sparse input when verbose=True
old_stdout = sys.stdout
sys.stdout = StringIO()
from scipy.sparse import csc_matrix
X = csc_matrix([[0.0], [1.0]])
rbm = BernoulliRBM(
n_components=2, batch_size=2, n_iter=1, random_state=42, verbose=True
)
try:
rbm.fit(X)
s = sys.stdout.getvalue()
# make sure output is sound
assert re.match(
r"\[BernoulliRBM\] Iteration 1,"
r" pseudo-likelihood = -?(\d)+(\.\d+)?,"
r" time = (\d|\.)+s",
s,
)
finally:
sys.stdout = old_stdout
@pytest.mark.parametrize(
"dtype_in, dtype_out",
[(np.float32, np.float32), (np.float64, np.float64), (int, np.float64)],
)
def test_transformer_dtypes_casting(dtype_in, dtype_out):
X = Xdigits[:100].astype(dtype_in)
rbm = BernoulliRBM(n_components=16, batch_size=5, n_iter=5, random_state=42)
Xt = rbm.fit_transform(X)
# dtype_in and dtype_out should be consistent
assert Xt.dtype == dtype_out, "transform dtype: {} - original dtype: {}".format(
Xt.dtype, X.dtype
)
def test_convergence_dtype_consistency():
# float 64 transformer
X_64 = Xdigits[:100].astype(np.float64)
rbm_64 = BernoulliRBM(n_components=16, batch_size=5, n_iter=5, random_state=42)
Xt_64 = rbm_64.fit_transform(X_64)
# float 32 transformer
X_32 = Xdigits[:100].astype(np.float32)
rbm_32 = BernoulliRBM(n_components=16, batch_size=5, n_iter=5, random_state=42)
Xt_32 = rbm_32.fit_transform(X_32)
# results and attributes should be close enough in 32 bit and 64 bit
assert_allclose(Xt_64, Xt_32, rtol=1e-06, atol=0)
assert_allclose(
rbm_64.intercept_hidden_, rbm_32.intercept_hidden_, rtol=1e-06, atol=0
)
assert_allclose(
rbm_64.intercept_visible_, rbm_32.intercept_visible_, rtol=1e-05, atol=0
)
assert_allclose(rbm_64.components_, rbm_32.components_, rtol=1e-03, atol=0)
assert_allclose(rbm_64.h_samples_, rbm_32.h_samples_)
@pytest.mark.parametrize("method", ["fit", "partial_fit"])
def test_feature_names_out(method):
"""Check `get_feature_names_out` for `BernoulliRBM`."""
n_components = 10
rbm = BernoulliRBM(n_components=n_components)
getattr(rbm, method)(Xdigits)
names = rbm.get_feature_names_out()
expected_names = [f"bernoullirbm{i}" for i in range(n_components)]
assert_array_equal(expected_names, names)