test_neighbors.py 文件源码

def test_KNeighborsRegressor_multioutput_uniform_weight():
    # Test k-neighbors in multi-output regression with uniform weight
    rng = check_random_state(0)
    n_features = 5
    n_samples = 40
    n_output = 4

    X = rng.rand(n_samples, n_features)
    y = rng.rand(n_samples, n_output)

    X_train, X_test, y_train, y_test = train_test_split(X, y, random_state=0)
    for algorithm, weights in product(ALGORITHMS, [None, 'uniform']):
        knn = neighbors.KNeighborsRegressor(weights=weights,
                                            algorithm=algorithm)
        knn.fit(X_train, y_train)

        neigh_idx = knn.kneighbors(X_test, return_distance=False)
        y_pred_idx = np.array([np.mean(y_train[idx], axis=0)
                               for idx in neigh_idx])

        y_pred = knn.predict(X_test)

        assert_equal(y_pred.shape, y_test.shape)
        assert_equal(y_pred_idx.shape, y_test.shape)
        assert_array_almost_equal(y_pred, y_pred_idx)