Nearest Neighbour

nearest_neighbour.py

from scipy import spatial
import numpy as np
import time


def nearest_neighbour(points_a, points_b):
    tree = spatial.cKDTree(points_b)
    return tree.query(points_a)[1]


def test_random(n):
    points_a = np.random.rand(n, 2)*100
    points_b = np.random.rand(n, 2)*100

    start_time = time.time()
    result = nearest_neighbour(points_a, points_b)
    end_time = time.time()
    print("n = {:7d}, {:.3f} seconds".format(n, end_time - start_time))


def test_Michiel():
    points_a = np.array([[1, 3],[2, 4],[3, 5],[4, 6],[5, 7]])
    points_b = np.array([[2, 2.5],[4, 3.1],[2, 2.0],[3, 3.0],[6, 5.0]])
    print('Testdata from Michiel challenge:')
    print(points_a)
    print(points_b)
    print(nearest_neighbour(points_a, points_b))
    print()


if __name__ == "__main__":
    test_Michiel()

    for k in range(7):
        test_random(10**k)