test_neighbors.py 文件源码

def test_neighbors_iris():
    # Sanity checks on the iris dataset
    # Puts three points of each label in the plane and performs a
    # nearest neighbor query on points near the decision boundary.

    for algorithm in ALGORITHMS:
        clf = neighbors.KNeighborsClassifier(n_neighbors=1,
                                             algorithm=algorithm)
        clf.fit(iris.data, iris.target)
        assert_array_equal(clf.predict(iris.data), iris.target)

        clf.set_params(n_neighbors=9, algorithm=algorithm)
        clf.fit(iris.data, iris.target)
        assert_true(np.mean(clf.predict(iris.data) == iris.target) > 0.95)

        rgs = neighbors.KNeighborsRegressor(n_neighbors=5, algorithm=algorithm)
        rgs.fit(iris.data, iris.target)
        assert_greater(np.mean(rgs.predict(iris.data).round() == iris.target),
                       0.95)