computation of L2_distances

[Bear-kai]

I think the L2_distances in the function nearest_neighbour_correct should be computed as follows:
dis = pairs[0][i] - pairs[1][i]
dis = dis.reshape(dis.size)
L2_distances[i] = np.sqrt(dis.dot(dis))
instead of
L2_distances[i] = np.sum(np.sqrt(pairs[0][i]**2 - pairs[1][i]**2))

[jinwu07]

Or simply:
L2_distances[i] = np.linalg.norm((pairs[0][i]- pairs[1][i]).reshape(-1), ord=2)
The original code isn't quite right.