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

464 lines
16 KiB
Python

import functools
from typing import List, Any
import warnings
import numpy as np
import scipy.sparse as sp
import pytest
from sklearn.metrics import euclidean_distances
from sklearn.random_projection import johnson_lindenstrauss_min_dim
from sklearn.random_projection import _gaussian_random_matrix
from sklearn.random_projection import _sparse_random_matrix
from sklearn.random_projection import SparseRandomProjection
from sklearn.random_projection import GaussianRandomProjection
from sklearn.utils._testing import assert_allclose
from sklearn.utils._testing import assert_allclose_dense_sparse
from sklearn.utils._testing import assert_array_equal
from sklearn.utils._testing import assert_almost_equal
from sklearn.utils._testing import assert_array_almost_equal
from sklearn.exceptions import DataDimensionalityWarning
all_sparse_random_matrix: List[Any] = [_sparse_random_matrix]
all_dense_random_matrix: List[Any] = [_gaussian_random_matrix]
all_random_matrix = all_sparse_random_matrix + all_dense_random_matrix
all_SparseRandomProjection: List[Any] = [SparseRandomProjection]
all_DenseRandomProjection: List[Any] = [GaussianRandomProjection]
all_RandomProjection = all_SparseRandomProjection + all_DenseRandomProjection
# Make some random data with uniformly located non zero entries with
# Gaussian distributed values
def make_sparse_random_data(n_samples, n_features, n_nonzeros, random_state=0):
rng = np.random.RandomState(random_state)
data_coo = sp.coo_matrix(
(
rng.randn(n_nonzeros),
(
rng.randint(n_samples, size=n_nonzeros),
rng.randint(n_features, size=n_nonzeros),
),
),
shape=(n_samples, n_features),
)
return data_coo.toarray(), data_coo.tocsr()
def densify(matrix):
if not sp.issparse(matrix):
return matrix
else:
return matrix.toarray()
n_samples, n_features = (10, 1000)
n_nonzeros = int(n_samples * n_features / 100.0)
data, data_csr = make_sparse_random_data(n_samples, n_features, n_nonzeros)
###############################################################################
# test on JL lemma
###############################################################################
@pytest.mark.parametrize(
"n_samples, eps", [(100, 1.1), (100, 0.0), (100, -0.1), (0, 0.5)]
)
def test_invalid_jl_domain(n_samples, eps):
with pytest.raises(ValueError):
johnson_lindenstrauss_min_dim(n_samples, eps=eps)
def test_input_size_jl_min_dim():
with pytest.raises(ValueError):
johnson_lindenstrauss_min_dim(3 * [100], eps=2 * [0.9])
johnson_lindenstrauss_min_dim(
np.random.randint(1, 10, size=(10, 10)), eps=np.full((10, 10), 0.5)
)
###############################################################################
# tests random matrix generation
###############################################################################
def check_input_size_random_matrix(random_matrix):
inputs = [(0, 0), (-1, 1), (1, -1), (1, 0), (-1, 0)]
for n_components, n_features in inputs:
with pytest.raises(ValueError):
random_matrix(n_components, n_features)
def check_size_generated(random_matrix):
inputs = [(1, 5), (5, 1), (5, 5), (1, 1)]
for n_components, n_features in inputs:
assert random_matrix(n_components, n_features).shape == (
n_components,
n_features,
)
def check_zero_mean_and_unit_norm(random_matrix):
# All random matrix should produce a transformation matrix
# with zero mean and unit norm for each columns
A = densify(random_matrix(10000, 1, random_state=0))
assert_array_almost_equal(0, np.mean(A), 3)
assert_array_almost_equal(1.0, np.linalg.norm(A), 1)
def check_input_with_sparse_random_matrix(random_matrix):
n_components, n_features = 5, 10
for density in [-1.0, 0.0, 1.1]:
with pytest.raises(ValueError):
random_matrix(n_components, n_features, density=density)
@pytest.mark.parametrize("random_matrix", all_random_matrix)
def test_basic_property_of_random_matrix(random_matrix):
# Check basic properties of random matrix generation
check_input_size_random_matrix(random_matrix)
check_size_generated(random_matrix)
check_zero_mean_and_unit_norm(random_matrix)
@pytest.mark.parametrize("random_matrix", all_sparse_random_matrix)
def test_basic_property_of_sparse_random_matrix(random_matrix):
check_input_with_sparse_random_matrix(random_matrix)
random_matrix_dense = functools.partial(random_matrix, density=1.0)
check_zero_mean_and_unit_norm(random_matrix_dense)
def test_gaussian_random_matrix():
# Check some statical properties of Gaussian random matrix
# Check that the random matrix follow the proper distribution.
# Let's say that each element of a_{ij} of A is taken from
# a_ij ~ N(0.0, 1 / n_components).
#
n_components = 100
n_features = 1000
A = _gaussian_random_matrix(n_components, n_features, random_state=0)
assert_array_almost_equal(0.0, np.mean(A), 2)
assert_array_almost_equal(np.var(A, ddof=1), 1 / n_components, 1)
def test_sparse_random_matrix():
# Check some statical properties of sparse random matrix
n_components = 100
n_features = 500
for density in [0.3, 1.0]:
s = 1 / density
A = _sparse_random_matrix(
n_components, n_features, density=density, random_state=0
)
A = densify(A)
# Check possible values
values = np.unique(A)
assert np.sqrt(s) / np.sqrt(n_components) in values
assert -np.sqrt(s) / np.sqrt(n_components) in values
if density == 1.0:
assert np.size(values) == 2
else:
assert 0.0 in values
assert np.size(values) == 3
# Check that the random matrix follow the proper distribution.
# Let's say that each element of a_{ij} of A is taken from
#
# - -sqrt(s) / sqrt(n_components) with probability 1 / 2s
# - 0 with probability 1 - 1 / s
# - +sqrt(s) / sqrt(n_components) with probability 1 / 2s
#
assert_almost_equal(np.mean(A == 0.0), 1 - 1 / s, decimal=2)
assert_almost_equal(
np.mean(A == np.sqrt(s) / np.sqrt(n_components)), 1 / (2 * s), decimal=2
)
assert_almost_equal(
np.mean(A == -np.sqrt(s) / np.sqrt(n_components)), 1 / (2 * s), decimal=2
)
assert_almost_equal(np.var(A == 0.0, ddof=1), (1 - 1 / s) * 1 / s, decimal=2)
assert_almost_equal(
np.var(A == np.sqrt(s) / np.sqrt(n_components), ddof=1),
(1 - 1 / (2 * s)) * 1 / (2 * s),
decimal=2,
)
assert_almost_equal(
np.var(A == -np.sqrt(s) / np.sqrt(n_components), ddof=1),
(1 - 1 / (2 * s)) * 1 / (2 * s),
decimal=2,
)
###############################################################################
# tests on random projection transformer
###############################################################################
def test_random_projection_transformer_invalid_input():
n_components = "auto"
fit_data = [[0, 1, 2]]
for RandomProjection in all_RandomProjection:
with pytest.raises(ValueError):
RandomProjection(n_components=n_components).fit(fit_data)
def test_try_to_transform_before_fit():
for RandomProjection in all_RandomProjection:
with pytest.raises(ValueError):
RandomProjection(n_components="auto").transform(data)
def test_too_many_samples_to_find_a_safe_embedding():
data, _ = make_sparse_random_data(1000, 100, 1000)
for RandomProjection in all_RandomProjection:
rp = RandomProjection(n_components="auto", eps=0.1)
expected_msg = (
"eps=0.100000 and n_samples=1000 lead to a target dimension"
" of 5920 which is larger than the original space with"
" n_features=100"
)
with pytest.raises(ValueError, match=expected_msg):
rp.fit(data)
def test_random_projection_embedding_quality():
data, _ = make_sparse_random_data(8, 5000, 15000)
eps = 0.2
original_distances = euclidean_distances(data, squared=True)
original_distances = original_distances.ravel()
non_identical = original_distances != 0.0
# remove 0 distances to avoid division by 0
original_distances = original_distances[non_identical]
for RandomProjection in all_RandomProjection:
rp = RandomProjection(n_components="auto", eps=eps, random_state=0)
projected = rp.fit_transform(data)
projected_distances = euclidean_distances(projected, squared=True)
projected_distances = projected_distances.ravel()
# remove 0 distances to avoid division by 0
projected_distances = projected_distances[non_identical]
distances_ratio = projected_distances / original_distances
# check that the automatically tuned values for the density respect the
# contract for eps: pairwise distances are preserved according to the
# Johnson-Lindenstrauss lemma
assert distances_ratio.max() < 1 + eps
assert 1 - eps < distances_ratio.min()
def test_SparseRandomProj_output_representation():
for SparseRandomProj in all_SparseRandomProjection:
# when using sparse input, the projected data can be forced to be a
# dense numpy array
rp = SparseRandomProj(n_components=10, dense_output=True, random_state=0)
rp.fit(data)
assert isinstance(rp.transform(data), np.ndarray)
sparse_data = sp.csr_matrix(data)
assert isinstance(rp.transform(sparse_data), np.ndarray)
# the output can be left to a sparse matrix instead
rp = SparseRandomProj(n_components=10, dense_output=False, random_state=0)
rp = rp.fit(data)
# output for dense input will stay dense:
assert isinstance(rp.transform(data), np.ndarray)
# output for sparse output will be sparse:
assert sp.issparse(rp.transform(sparse_data))
def test_correct_RandomProjection_dimensions_embedding():
for RandomProjection in all_RandomProjection:
rp = RandomProjection(n_components="auto", random_state=0, eps=0.5).fit(data)
# the number of components is adjusted from the shape of the training
# set
assert rp.n_components == "auto"
assert rp.n_components_ == 110
if RandomProjection in all_SparseRandomProjection:
assert rp.density == "auto"
assert_almost_equal(rp.density_, 0.03, 2)
assert rp.components_.shape == (110, n_features)
projected_1 = rp.transform(data)
assert projected_1.shape == (n_samples, 110)
# once the RP is 'fitted' the projection is always the same
projected_2 = rp.transform(data)
assert_array_equal(projected_1, projected_2)
# fit transform with same random seed will lead to the same results
rp2 = RandomProjection(random_state=0, eps=0.5)
projected_3 = rp2.fit_transform(data)
assert_array_equal(projected_1, projected_3)
# Try to transform with an input X of size different from fitted.
with pytest.raises(ValueError):
rp.transform(data[:, 1:5])
# it is also possible to fix the number of components and the density
# level
if RandomProjection in all_SparseRandomProjection:
rp = RandomProjection(n_components=100, density=0.001, random_state=0)
projected = rp.fit_transform(data)
assert projected.shape == (n_samples, 100)
assert rp.components_.shape == (100, n_features)
assert rp.components_.nnz < 115 # close to 1% density
assert 85 < rp.components_.nnz # close to 1% density
def test_warning_n_components_greater_than_n_features():
n_features = 20
data, _ = make_sparse_random_data(5, n_features, int(n_features / 4))
for RandomProjection in all_RandomProjection:
with pytest.warns(DataDimensionalityWarning):
RandomProjection(n_components=n_features + 1).fit(data)
def test_works_with_sparse_data():
n_features = 20
data, _ = make_sparse_random_data(5, n_features, int(n_features / 4))
for RandomProjection in all_RandomProjection:
rp_dense = RandomProjection(n_components=3, random_state=1).fit(data)
rp_sparse = RandomProjection(n_components=3, random_state=1).fit(
sp.csr_matrix(data)
)
assert_array_almost_equal(
densify(rp_dense.components_), densify(rp_sparse.components_)
)
def test_johnson_lindenstrauss_min_dim():
"""Test Johnson-Lindenstrauss for small eps.
Regression test for #17111: before #19374, 32-bit systems would fail.
"""
assert johnson_lindenstrauss_min_dim(100, eps=1e-5) == 368416070986
@pytest.mark.parametrize("random_projection_cls", all_RandomProjection)
def test_random_projection_feature_names_out(random_projection_cls):
random_projection = random_projection_cls(n_components=2)
random_projection.fit(data)
names_out = random_projection.get_feature_names_out()
class_name_lower = random_projection_cls.__name__.lower()
expected_names_out = np.array(
[f"{class_name_lower}{i}" for i in range(random_projection.n_components_)],
dtype=object,
)
assert_array_equal(names_out, expected_names_out)
@pytest.mark.parametrize("n_samples", (2, 9, 10, 11, 1000))
@pytest.mark.parametrize("n_features", (2, 9, 10, 11, 1000))
@pytest.mark.parametrize("random_projection_cls", all_RandomProjection)
@pytest.mark.parametrize("compute_inverse_components", [True, False])
def test_inverse_transform(
n_samples,
n_features,
random_projection_cls,
compute_inverse_components,
global_random_seed,
):
n_components = 10
random_projection = random_projection_cls(
n_components=n_components,
compute_inverse_components=compute_inverse_components,
random_state=global_random_seed,
)
X_dense, X_csr = make_sparse_random_data(
n_samples,
n_features,
n_samples * n_features // 100 + 1,
random_state=global_random_seed,
)
for X in [X_dense, X_csr]:
with warnings.catch_warnings():
warnings.filterwarnings(
"ignore",
message=(
"The number of components is higher than the number of features"
),
category=DataDimensionalityWarning,
)
projected = random_projection.fit_transform(X)
if compute_inverse_components:
assert hasattr(random_projection, "inverse_components_")
inv_components = random_projection.inverse_components_
assert inv_components.shape == (n_features, n_components)
projected_back = random_projection.inverse_transform(projected)
assert projected_back.shape == X.shape
projected_again = random_projection.transform(projected_back)
if hasattr(projected, "toarray"):
projected = projected.toarray()
assert_allclose(projected, projected_again, rtol=1e-7, atol=1e-10)
@pytest.mark.parametrize("random_projection_cls", all_RandomProjection)
@pytest.mark.parametrize(
"input_dtype, expected_dtype",
(
(np.float32, np.float32),
(np.float64, np.float64),
(np.int32, np.float64),
(np.int64, np.float64),
),
)
def test_random_projection_dtype_match(
random_projection_cls, input_dtype, expected_dtype
):
# Verify output matrix dtype
rng = np.random.RandomState(42)
X = rng.rand(25, 3000)
rp = random_projection_cls(random_state=0)
transformed = rp.fit_transform(X.astype(input_dtype))
assert rp.components_.dtype == expected_dtype
assert transformed.dtype == expected_dtype
@pytest.mark.parametrize("random_projection_cls", all_RandomProjection)
def test_random_projection_numerical_consistency(random_projection_cls):
# Verify numerical consistency among np.float32 and np.float64
atol = 1e-5
rng = np.random.RandomState(42)
X = rng.rand(25, 3000)
rp_32 = random_projection_cls(random_state=0)
rp_64 = random_projection_cls(random_state=0)
projection_32 = rp_32.fit_transform(X.astype(np.float32))
projection_64 = rp_64.fit_transform(X.astype(np.float64))
assert_allclose(projection_64, projection_32, atol=atol)
assert_allclose_dense_sparse(rp_32.components_, rp_64.components_)