scikit-learn/sklearn/linear_model/tests/test_base.py

87 lines
2.5 KiB
Python

# Author: Alexandre Gramfort <alexandre.gramfort@inria.fr>
# Fabian Pedregosa <fabian.pedregosa@inria.fr>
#
# License: BSD Style.
from numpy.testing import assert_array_almost_equal, assert_equal
import numpy as np
from scipy import sparse
from ..base import LinearRegression
from ...utils import check_random_state
from ...datasets.samples_generator import make_sparse_uncorrelated
from ...datasets.samples_generator import make_regression
def test_linear_regression():
"""
Test LinearRegression on a simple dataset.
"""
# a simple dataset
X = [[1], [2]]
Y = [1, 2]
clf = LinearRegression()
clf.fit(X, Y)
assert_array_almost_equal(clf.coef_, [1])
assert_array_almost_equal(clf.intercept_, [0])
assert_array_almost_equal(clf.predict(X), [1, 2])
# test it also for degenerate input
X = [[1]]
Y = [0]
clf = LinearRegression()
clf.fit(X, Y)
assert_array_almost_equal(clf.coef_, [0])
assert_array_almost_equal(clf.intercept_, [0])
assert_array_almost_equal(clf.predict(X), [0])
def test_linear_regression_sparse(random_state=0):
"Test that linear regression also works with sparse data"
random_state = check_random_state(random_state)
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.residues_, 0)
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]
clf = LinearRegression(fit_intercept=True)
clf.fit((X), Y)
assert_equal(clf.coef_.shape, (2, n_features))
Y_pred = clf.predict(X)
clf.fit(X, y)
y_pred = clf.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_equal(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)