test_validation.py 文件源码

def test_cross_val_score_precomputed():
    # test for svm with precomputed kernel
    svm = SVC(kernel="precomputed")
    iris = load_iris()
    X, y = iris.data, iris.target
    linear_kernel = np.dot(X, X.T)
    score_precomputed = cross_val_score(svm, linear_kernel, y)
    svm = SVC(kernel="linear")
    score_linear = cross_val_score(svm, X, y)
    assert_array_equal(score_precomputed, score_linear)

    # Error raised for non-square X
    svm = SVC(kernel="precomputed")
    assert_raises(ValueError, cross_val_score, svm, X, y)

    # test error is raised when the precomputed kernel is not array-like
    # or sparse
    assert_raises(ValueError, cross_val_score, svm,
                  linear_kernel.tolist(), y)