scikit-learn/sklearn/feature_selection/tests/test_rfe.py

57 lines
1.5 KiB
Python

"""
Testing Recursive feature elimination
"""
import numpy as np
from numpy.testing import assert_array_almost_equal
from ..rfe import RFE, RFECV
from ...datasets import load_iris
from ...metrics import zero_one
from ...svm import SVC
from ...utils import check_random_state
def test_rfe():
generator = check_random_state(0)
iris = load_iris()
X = np.c_[iris.data, generator.normal(size=(len(iris.data), 6))]
y = iris.target
clf = SVC(kernel="linear")
rfe = RFE(estimator=clf, n_features_to_select=4, step=0.1)
rfe.fit(X, y)
X_r = rfe.transform(X)
assert X_r.shape == iris.data.shape
assert_array_almost_equal(X_r[:10], iris.data[:10])
assert_array_almost_equal(rfe.predict(X), clf.predict(iris.data))
assert rfe.score(X, y) == clf.score(iris.data, iris.target)
def test_rfecv():
generator = check_random_state(0)
iris = load_iris()
X = np.c_[iris.data, generator.normal(size=(len(iris.data), 6))]
y = iris.target
# Test using the score function
rfecv = RFECV(estimator=SVC(kernel="linear"), step=1, cv=3)
rfecv.fit(X, y)
X_r = rfecv.transform(X)
assert X_r.shape == iris.data.shape
assert_array_almost_equal(X_r[:10], iris.data[:10])
# Test using a customized loss function
rfecv = RFECV(estimator=SVC(kernel="linear"), step=1, cv=3,
loss_func=zero_one)
rfecv.fit(X, y)
X_r = rfecv.transform(X)
assert X_r.shape == iris.data.shape
assert_array_almost_equal(X_r[:10], iris.data[:10])