projektAI/venv/Lib/site-packages/sklearn/linear_model/tests/test_base.py

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2021-06-06 22:13:05 +02:00
# Author: Alexandre Gramfort <alexandre.gramfort@inria.fr>
# Fabian Pedregosa <fabian.pedregosa@inria.fr>
#
# License: BSD 3 clause
import pytest
import numpy as np
from scipy import sparse
from scipy import linalg
from sklearn.utils._testing import assert_array_almost_equal
from sklearn.utils._testing import assert_array_equal
from sklearn.utils._testing import assert_almost_equal
from sklearn.utils._testing import assert_allclose
from sklearn.utils import check_random_state
from sklearn.utils.fixes import parse_version
from sklearn.linear_model import LinearRegression
from sklearn.linear_model._base import _preprocess_data
from sklearn.linear_model._base import _rescale_data
from sklearn.linear_model._base import make_dataset
from sklearn.datasets import make_sparse_uncorrelated
from sklearn.datasets import make_regression
from sklearn.datasets import load_iris
rng = np.random.RandomState(0)
rtol = 1e-6
def test_linear_regression():
# Test LinearRegression on a simple dataset.
# a simple dataset
X = [[1], [2]]
Y = [1, 2]
reg = LinearRegression()
reg.fit(X, Y)
assert_array_almost_equal(reg.coef_, [1])
assert_array_almost_equal(reg.intercept_, [0])
assert_array_almost_equal(reg.predict(X), [1, 2])
# test it also for degenerate input
X = [[1]]
Y = [0]
reg = LinearRegression()
reg.fit(X, Y)
assert_array_almost_equal(reg.coef_, [0])
assert_array_almost_equal(reg.intercept_, [0])
assert_array_almost_equal(reg.predict(X), [0])
def test_linear_regression_sample_weights():
# TODO: loop over sparse data as well
rng = np.random.RandomState(0)
# It would not work with under-determined systems
for n_samples, n_features in ((6, 5), ):
y = rng.randn(n_samples)
X = rng.randn(n_samples, n_features)
sample_weight = 1.0 + rng.rand(n_samples)
for intercept in (True, False):
# LinearRegression with explicit sample_weight
reg = LinearRegression(fit_intercept=intercept)
reg.fit(X, y, sample_weight=sample_weight)
coefs1 = reg.coef_
inter1 = reg.intercept_
assert reg.coef_.shape == (X.shape[1], ) # sanity checks
assert reg.score(X, y) > 0.5
# Closed form of the weighted least square
# theta = (X^T W X)^(-1) * X^T W y
W = np.diag(sample_weight)
if intercept is False:
X_aug = X
else:
dummy_column = np.ones(shape=(n_samples, 1))
X_aug = np.concatenate((dummy_column, X), axis=1)
coefs2 = linalg.solve(X_aug.T.dot(W).dot(X_aug),
X_aug.T.dot(W).dot(y))
if intercept is False:
assert_array_almost_equal(coefs1, coefs2)
else:
assert_array_almost_equal(coefs1, coefs2[1:])
assert_almost_equal(inter1, coefs2[0])
def test_raises_value_error_if_positive_and_sparse():
error_msg = ('A sparse matrix was passed, '
'but dense data is required.')
# X must not be sparse if positive == True
X = sparse.eye(10)
y = np.ones(10)
reg = LinearRegression(positive=True)
with pytest.raises(TypeError, match=error_msg):
reg.fit(X, y)
def test_raises_value_error_if_sample_weights_greater_than_1d():
# Sample weights must be either scalar or 1D
n_sampless = [2, 3]
n_featuress = [3, 2]
for n_samples, n_features in zip(n_sampless, n_featuress):
X = rng.randn(n_samples, n_features)
y = rng.randn(n_samples)
sample_weights_OK = rng.randn(n_samples) ** 2 + 1
sample_weights_OK_1 = 1.
sample_weights_OK_2 = 2.
reg = LinearRegression()
# make sure the "OK" sample weights actually work
reg.fit(X, y, sample_weights_OK)
reg.fit(X, y, sample_weights_OK_1)
reg.fit(X, y, sample_weights_OK_2)
def test_fit_intercept():
# Test assertions on betas shape.
X2 = np.array([[0.38349978, 0.61650022],
[0.58853682, 0.41146318]])
X3 = np.array([[0.27677969, 0.70693172, 0.01628859],
[0.08385139, 0.20692515, 0.70922346]])
y = np.array([1, 1])
lr2_without_intercept = LinearRegression(fit_intercept=False).fit(X2, y)
lr2_with_intercept = LinearRegression().fit(X2, y)
lr3_without_intercept = LinearRegression(fit_intercept=False).fit(X3, y)
lr3_with_intercept = LinearRegression().fit(X3, y)
assert (lr2_with_intercept.coef_.shape ==
lr2_without_intercept.coef_.shape)
assert (lr3_with_intercept.coef_.shape ==
lr3_without_intercept.coef_.shape)
assert (lr2_without_intercept.coef_.ndim ==
lr3_without_intercept.coef_.ndim)
def test_linear_regression_sparse(random_state=0):
# Test that linear regression also works with sparse data
random_state = check_random_state(random_state)
for i in range(10):
n = 100
X = sparse.eye(n, n)
beta = random_state.rand(n)
y = X * beta[:, np.newaxis]
ols = LinearRegression()
ols.fit(X, y.ravel())
assert_array_almost_equal(beta, ols.coef_ + ols.intercept_)
assert_array_almost_equal(ols.predict(X) - y.ravel(), 0)
@pytest.mark.parametrize('normalize', [True, False])
@pytest.mark.parametrize('fit_intercept', [True, False])
def test_linear_regression_sparse_equal_dense(normalize, fit_intercept):
# Test that linear regression agrees between sparse and dense
rng = check_random_state(0)
n_samples = 200
n_features = 2
X = rng.randn(n_samples, n_features)
X[X < 0.1] = 0.
Xcsr = sparse.csr_matrix(X)
y = rng.rand(n_samples)
params = dict(normalize=normalize, fit_intercept=fit_intercept)
clf_dense = LinearRegression(**params)
clf_sparse = LinearRegression(**params)
clf_dense.fit(X, y)
clf_sparse.fit(Xcsr, y)
assert clf_dense.intercept_ == pytest.approx(clf_sparse.intercept_)
assert_allclose(clf_dense.coef_, clf_sparse.coef_)
def test_linear_regression_multiple_outcome(random_state=0):
# Test multiple-outcome linear regressions
X, y = make_regression(random_state=random_state)
Y = np.vstack((y, y)).T
n_features = X.shape[1]
reg = LinearRegression()
reg.fit((X), Y)
assert reg.coef_.shape == (2, n_features)
Y_pred = reg.predict(X)
reg.fit(X, y)
y_pred = reg.predict(X)
assert_array_almost_equal(np.vstack((y_pred, y_pred)).T, Y_pred, decimal=3)
def test_linear_regression_sparse_multiple_outcome(random_state=0):
# Test multiple-outcome linear regressions with sparse data
random_state = check_random_state(random_state)
X, y = make_sparse_uncorrelated(random_state=random_state)
X = sparse.coo_matrix(X)
Y = np.vstack((y, y)).T
n_features = X.shape[1]
ols = LinearRegression()
ols.fit(X, Y)
assert ols.coef_.shape == (2, n_features)
Y_pred = ols.predict(X)
ols.fit(X, y.ravel())
y_pred = ols.predict(X)
assert_array_almost_equal(np.vstack((y_pred, y_pred)).T, Y_pred, decimal=3)
def test_linear_regression_positive():
# Test nonnegative LinearRegression on a simple dataset.
X = [[1], [2]]
y = [1, 2]
reg = LinearRegression(positive=True)
reg.fit(X, y)
assert_array_almost_equal(reg.coef_, [1])
assert_array_almost_equal(reg.intercept_, [0])
assert_array_almost_equal(reg.predict(X), [1, 2])
# test it also for degenerate input
X = [[1]]
y = [0]
reg = LinearRegression(positive=True)
reg.fit(X, y)
assert_allclose(reg.coef_, [0])
assert_allclose(reg.intercept_, [0])
assert_allclose(reg.predict(X), [0])
def test_linear_regression_positive_multiple_outcome(random_state=0):
# Test multiple-outcome nonnegative linear regressions
random_state = check_random_state(random_state)
X, y = make_sparse_uncorrelated(random_state=random_state)
Y = np.vstack((y, y)).T
n_features = X.shape[1]
ols = LinearRegression(positive=True)
ols.fit(X, Y)
assert ols.coef_.shape == (2, n_features)
assert np.all(ols.coef_ >= 0.)
Y_pred = ols.predict(X)
ols.fit(X, y.ravel())
y_pred = ols.predict(X)
assert_allclose(np.vstack((y_pred, y_pred)).T, Y_pred)
def test_linear_regression_positive_vs_nonpositive():
# Test differences with LinearRegression when positive=False.
X, y = make_sparse_uncorrelated(random_state=0)
reg = LinearRegression(positive=True)
reg.fit(X, y)
regn = LinearRegression(positive=False)
regn.fit(X, y)
assert np.mean((reg.coef_ - regn.coef_)**2) > 1e-3
def test_linear_regression_positive_vs_nonpositive_when_positive():
# Test LinearRegression fitted coefficients
# when the problem is positive.
n_samples = 200
n_features = 4
X = rng.rand(n_samples, n_features)
y = X[:, 0] + 2 * X[:, 1] + 3 * X[:, 2] + 1.5 * X[:, 3]
reg = LinearRegression(positive=True)
reg.fit(X, y)
regn = LinearRegression(positive=False)
regn.fit(X, y)
assert np.mean((reg.coef_ - regn.coef_)**2) < 1e-6
def test_linear_regression_pd_sparse_dataframe_warning():
pd = pytest.importorskip('pandas')
# restrict the pd versions < '0.24.0' as they have a bug in is_sparse func
if parse_version(pd.__version__) < parse_version('0.24.0'):
pytest.skip("pandas 0.24+ required.")
# Warning is raised only when some of the columns is sparse
df = pd.DataFrame({'0': np.random.randn(10)})
for col in range(1, 4):
arr = np.random.randn(10)
arr[:8] = 0
# all columns but the first column is sparse
if col != 0:
arr = pd.arrays.SparseArray(arr, fill_value=0)
df[str(col)] = arr
msg = "pandas.DataFrame with sparse columns found."
with pytest.warns(UserWarning, match=msg):
reg = LinearRegression()
reg.fit(df.iloc[:, 0:2], df.iloc[:, 3])
# does not warn when the whole dataframe is sparse
df['0'] = pd.arrays.SparseArray(df['0'], fill_value=0)
assert hasattr(df, "sparse")
with pytest.warns(None) as record:
reg.fit(df.iloc[:, 0:2], df.iloc[:, 3])
assert not record
def test_preprocess_data():
n_samples = 200
n_features = 2
X = rng.rand(n_samples, n_features)
y = rng.rand(n_samples)
expected_X_mean = np.mean(X, axis=0)
expected_X_norm = np.std(X, axis=0) * np.sqrt(X.shape[0])
expected_y_mean = np.mean(y, axis=0)
Xt, yt, X_mean, y_mean, X_norm = \
_preprocess_data(X, y, fit_intercept=False, normalize=False)
assert_array_almost_equal(X_mean, np.zeros(n_features))
assert_array_almost_equal(y_mean, 0)
assert_array_almost_equal(X_norm, np.ones(n_features))
assert_array_almost_equal(Xt, X)
assert_array_almost_equal(yt, y)
Xt, yt, X_mean, y_mean, X_norm = \
_preprocess_data(X, y, fit_intercept=True, normalize=False)
assert_array_almost_equal(X_mean, expected_X_mean)
assert_array_almost_equal(y_mean, expected_y_mean)
assert_array_almost_equal(X_norm, np.ones(n_features))
assert_array_almost_equal(Xt, X - expected_X_mean)
assert_array_almost_equal(yt, y - expected_y_mean)
Xt, yt, X_mean, y_mean, X_norm = \
_preprocess_data(X, y, fit_intercept=True, normalize=True)
assert_array_almost_equal(X_mean, expected_X_mean)
assert_array_almost_equal(y_mean, expected_y_mean)
assert_array_almost_equal(X_norm, expected_X_norm)
assert_array_almost_equal(Xt, (X - expected_X_mean) / expected_X_norm)
assert_array_almost_equal(yt, y - expected_y_mean)
def test_preprocess_data_multioutput():
n_samples = 200
n_features = 3
n_outputs = 2
X = rng.rand(n_samples, n_features)
y = rng.rand(n_samples, n_outputs)
expected_y_mean = np.mean(y, axis=0)
args = [X, sparse.csc_matrix(X)]
for X in args:
_, yt, _, y_mean, _ = _preprocess_data(X, y, fit_intercept=False,
normalize=False)
assert_array_almost_equal(y_mean, np.zeros(n_outputs))
assert_array_almost_equal(yt, y)
_, yt, _, y_mean, _ = _preprocess_data(X, y, fit_intercept=True,
normalize=False)
assert_array_almost_equal(y_mean, expected_y_mean)
assert_array_almost_equal(yt, y - y_mean)
_, yt, _, y_mean, _ = _preprocess_data(X, y, fit_intercept=True,
normalize=True)
assert_array_almost_equal(y_mean, expected_y_mean)
assert_array_almost_equal(yt, y - y_mean)
def test_preprocess_data_weighted():
n_samples = 200
n_features = 2
X = rng.rand(n_samples, n_features)
y = rng.rand(n_samples)
sample_weight = rng.rand(n_samples)
expected_X_mean = np.average(X, axis=0, weights=sample_weight)
expected_y_mean = np.average(y, axis=0, weights=sample_weight)
# XXX: if normalize=True, should we expect a weighted standard deviation?
# Currently not weighted, but calculated with respect to weighted mean
expected_X_norm = (np.sqrt(X.shape[0]) *
np.mean((X - expected_X_mean) ** 2, axis=0) ** .5)
Xt, yt, X_mean, y_mean, X_norm = \
_preprocess_data(X, y, fit_intercept=True, normalize=False,
sample_weight=sample_weight)
assert_array_almost_equal(X_mean, expected_X_mean)
assert_array_almost_equal(y_mean, expected_y_mean)
assert_array_almost_equal(X_norm, np.ones(n_features))
assert_array_almost_equal(Xt, X - expected_X_mean)
assert_array_almost_equal(yt, y - expected_y_mean)
Xt, yt, X_mean, y_mean, X_norm = \
_preprocess_data(X, y, fit_intercept=True, normalize=True,
sample_weight=sample_weight)
assert_array_almost_equal(X_mean, expected_X_mean)
assert_array_almost_equal(y_mean, expected_y_mean)
assert_array_almost_equal(X_norm, expected_X_norm)
assert_array_almost_equal(Xt, (X - expected_X_mean) / expected_X_norm)
assert_array_almost_equal(yt, y - expected_y_mean)
def test_sparse_preprocess_data_with_return_mean():
n_samples = 200
n_features = 2
# random_state not supported yet in sparse.rand
X = sparse.rand(n_samples, n_features, density=.5) # , random_state=rng
X = X.tolil()
y = rng.rand(n_samples)
XA = X.toarray()
expected_X_norm = np.std(XA, axis=0) * np.sqrt(X.shape[0])
Xt, yt, X_mean, y_mean, X_norm = \
_preprocess_data(X, y, fit_intercept=False, normalize=False,
return_mean=True)
assert_array_almost_equal(X_mean, np.zeros(n_features))
assert_array_almost_equal(y_mean, 0)
assert_array_almost_equal(X_norm, np.ones(n_features))
assert_array_almost_equal(Xt.A, XA)
assert_array_almost_equal(yt, y)
Xt, yt, X_mean, y_mean, X_norm = \
_preprocess_data(X, y, fit_intercept=True, normalize=False,
return_mean=True)
assert_array_almost_equal(X_mean, np.mean(XA, axis=0))
assert_array_almost_equal(y_mean, np.mean(y, axis=0))
assert_array_almost_equal(X_norm, np.ones(n_features))
assert_array_almost_equal(Xt.A, XA)
assert_array_almost_equal(yt, y - np.mean(y, axis=0))
Xt, yt, X_mean, y_mean, X_norm = \
_preprocess_data(X, y, fit_intercept=True, normalize=True,
return_mean=True)
assert_array_almost_equal(X_mean, np.mean(XA, axis=0))
assert_array_almost_equal(y_mean, np.mean(y, axis=0))
assert_array_almost_equal(X_norm, expected_X_norm)
assert_array_almost_equal(Xt.A, XA / expected_X_norm)
assert_array_almost_equal(yt, y - np.mean(y, axis=0))
def test_csr_preprocess_data():
# Test output format of _preprocess_data, when input is csr
X, y = make_regression()
X[X < 2.5] = 0.0
csr = sparse.csr_matrix(X)
csr_, y, _, _, _ = _preprocess_data(csr, y, True)
assert csr_.getformat() == 'csr'
@pytest.mark.parametrize('is_sparse', (True, False))
@pytest.mark.parametrize('to_copy', (True, False))
def test_preprocess_copy_data_no_checks(is_sparse, to_copy):
X, y = make_regression()
X[X < 2.5] = 0.0
if is_sparse:
X = sparse.csr_matrix(X)
X_, y_, _, _, _ = _preprocess_data(X, y, True,
copy=to_copy, check_input=False)
if to_copy and is_sparse:
assert not np.may_share_memory(X_.data, X.data)
elif to_copy:
assert not np.may_share_memory(X_, X)
elif is_sparse:
assert np.may_share_memory(X_.data, X.data)
else:
assert np.may_share_memory(X_, X)
def test_dtype_preprocess_data():
n_samples = 200
n_features = 2
X = rng.rand(n_samples, n_features)
y = rng.rand(n_samples)
X_32 = np.asarray(X, dtype=np.float32)
y_32 = np.asarray(y, dtype=np.float32)
X_64 = np.asarray(X, dtype=np.float64)
y_64 = np.asarray(y, dtype=np.float64)
for fit_intercept in [True, False]:
for normalize in [True, False]:
Xt_32, yt_32, X_mean_32, y_mean_32, X_norm_32 = _preprocess_data(
X_32, y_32, fit_intercept=fit_intercept, normalize=normalize,
return_mean=True)
Xt_64, yt_64, X_mean_64, y_mean_64, X_norm_64 = _preprocess_data(
X_64, y_64, fit_intercept=fit_intercept, normalize=normalize,
return_mean=True)
Xt_3264, yt_3264, X_mean_3264, y_mean_3264, X_norm_3264 = (
_preprocess_data(X_32, y_64, fit_intercept=fit_intercept,
normalize=normalize, return_mean=True))
Xt_6432, yt_6432, X_mean_6432, y_mean_6432, X_norm_6432 = (
_preprocess_data(X_64, y_32, fit_intercept=fit_intercept,
normalize=normalize, return_mean=True))
assert Xt_32.dtype == np.float32
assert yt_32.dtype == np.float32
assert X_mean_32.dtype == np.float32
assert y_mean_32.dtype == np.float32
assert X_norm_32.dtype == np.float32
assert Xt_64.dtype == np.float64
assert yt_64.dtype == np.float64
assert X_mean_64.dtype == np.float64
assert y_mean_64.dtype == np.float64
assert X_norm_64.dtype == np.float64
assert Xt_3264.dtype == np.float32
assert yt_3264.dtype == np.float32
assert X_mean_3264.dtype == np.float32
assert y_mean_3264.dtype == np.float32
assert X_norm_3264.dtype == np.float32
assert Xt_6432.dtype == np.float64
assert yt_6432.dtype == np.float64
assert X_mean_6432.dtype == np.float64
assert y_mean_6432.dtype == np.float64
assert X_norm_6432.dtype == np.float64
assert X_32.dtype == np.float32
assert y_32.dtype == np.float32
assert X_64.dtype == np.float64
assert y_64.dtype == np.float64
assert_array_almost_equal(Xt_32, Xt_64)
assert_array_almost_equal(yt_32, yt_64)
assert_array_almost_equal(X_mean_32, X_mean_64)
assert_array_almost_equal(y_mean_32, y_mean_64)
assert_array_almost_equal(X_norm_32, X_norm_64)
@pytest.mark.parametrize('n_targets', [None, 2])
def test_rescale_data_dense(n_targets):
n_samples = 200
n_features = 2
sample_weight = 1.0 + rng.rand(n_samples)
X = rng.rand(n_samples, n_features)
if n_targets is None:
y = rng.rand(n_samples)
else:
y = rng.rand(n_samples, n_targets)
rescaled_X, rescaled_y = _rescale_data(X, y, sample_weight)
rescaled_X2 = X * np.sqrt(sample_weight)[:, np.newaxis]
if n_targets is None:
rescaled_y2 = y * np.sqrt(sample_weight)
else:
rescaled_y2 = y * np.sqrt(sample_weight)[:, np.newaxis]
assert_array_almost_equal(rescaled_X, rescaled_X2)
assert_array_almost_equal(rescaled_y, rescaled_y2)
def test_fused_types_make_dataset():
iris = load_iris()
X_32 = iris.data.astype(np.float32)
y_32 = iris.target.astype(np.float32)
X_csr_32 = sparse.csr_matrix(X_32)
sample_weight_32 = np.arange(y_32.size, dtype=np.float32)
X_64 = iris.data.astype(np.float64)
y_64 = iris.target.astype(np.float64)
X_csr_64 = sparse.csr_matrix(X_64)
sample_weight_64 = np.arange(y_64.size, dtype=np.float64)
# array
dataset_32, _ = make_dataset(X_32, y_32, sample_weight_32)
dataset_64, _ = make_dataset(X_64, y_64, sample_weight_64)
xi_32, yi_32, _, _ = dataset_32._next_py()
xi_64, yi_64, _, _ = dataset_64._next_py()
xi_data_32, _, _ = xi_32
xi_data_64, _, _ = xi_64
assert xi_data_32.dtype == np.float32
assert xi_data_64.dtype == np.float64
assert_allclose(yi_64, yi_32, rtol=rtol)
# csr
datasetcsr_32, _ = make_dataset(X_csr_32, y_32, sample_weight_32)
datasetcsr_64, _ = make_dataset(X_csr_64, y_64, sample_weight_64)
xicsr_32, yicsr_32, _, _ = datasetcsr_32._next_py()
xicsr_64, yicsr_64, _, _ = datasetcsr_64._next_py()
xicsr_data_32, _, _ = xicsr_32
xicsr_data_64, _, _ = xicsr_64
assert xicsr_data_32.dtype == np.float32
assert xicsr_data_64.dtype == np.float64
assert_allclose(xicsr_data_64, xicsr_data_32, rtol=rtol)
assert_allclose(yicsr_64, yicsr_32, rtol=rtol)
assert_array_equal(xi_data_32, xicsr_data_32)
assert_array_equal(xi_data_64, xicsr_data_64)
assert_array_equal(yi_32, yicsr_32)
assert_array_equal(yi_64, yicsr_64)