import pdb

import numpy as np

n = 20
m = 200
d = 128

# make reproducible
np.random.seed(0)
X = np.random.random((n, d))
Y = np.random.random((m, d))

# squared pariwise distances
pairwise_distances = np.empty((n, m))
nn_index = np.empty(n, dtype = int)

for i in range(n): 
    nearest_dist = np.inf
    for j in range(m): 
        dist = pairwise_distances[i, j] = ((X[i] - Y[j]) ** 2).sum()
        if dist < nearest_dist: 
            nearest_dist = dist 
            nearest_index = j
    nn_index[i] = nearest_index

print "indices of nearest-neighbors:", nn_index