test_text.py 文件源码

def test_tf_idf_smoothing():
    X = [[1, 1, 1],
         [1, 1, 0],
         [1, 0, 0]]
    tr = TfidfTransformer(smooth_idf=True, norm='l2')
    tfidf = tr.fit_transform(X).toarray()
    assert_true((tfidf >= 0).all())

    # check normalization
    assert_array_almost_equal((tfidf ** 2).sum(axis=1), [1., 1., 1.])

    # this is robust to features with only zeros
    X = [[1, 1, 0],
         [1, 1, 0],
         [1, 0, 0]]
    tr = TfidfTransformer(smooth_idf=True, norm='l2')
    tfidf = tr.fit_transform(X).toarray()
    assert_true((tfidf >= 0).all())