test_variance_threshold.py 文件源码

def test_zero_variance():
    # Test VarianceThreshold with default setting, zero variance.

    for X in [data, csr_matrix(data), csc_matrix(data), bsr_matrix(data)]:
        sel = VarianceThreshold().fit(X)
        assert_array_equal([0, 1, 3, 4], sel.get_support(indices=True))

    assert_raises(ValueError, VarianceThreshold().fit, [[0, 1, 2, 3]])
    assert_raises(ValueError, VarianceThreshold().fit, [[0, 1], [0, 1]])