random_hamming_dist

random_hamming_dist.py

#!/usr/bin/python 
# -*- coding:UTF-8 -*-
import numpy as np

def main():
    random_hamming_dist() 

def random_hamming_dist():
    def hamming_dist(a, b, bits=32):
        x = a ^ b 
        dist = sum((x >> i & 1) for i in xrange(bits))
        return dist
    test_size = 20000 
    half_test_size = 10000 
    eva = []
    ri = np.random.random_integers(0,1<<32,test_size)
    for i in xrange(half_test_size):
        eva.append(hamming_dist(ri[i], ri[i+half_test_size]))
    stat = [0] * 32
    for each in eva:
        stat[each] +=1
    width = 76.
    norm = width / np.max(stat)
    for i in xrange(32):
        print i,':',
        print '*' * int(stat[i] * norm),
        print ''
'''the result is expect to be something like:

0  :  
1  :  
2  :  
3  :  
4  :  
5  :  
6  :  
7  :  
8  : * 
9  : *** 
10 : ****** 
11 : ****************** 
12 : **************************** 
13 : ***************************************** 
14 : ************************************************************ 
15 : ********************************************************************* 
16 : **************************************************************************** 
17 : ********************************************************************* 
18 : ********************************************************** 
19 : ****************************************** 
20 : ***************************** 
21 : ***************** 
22 : ******* 
23 : ** 
24 : * 
25 :  
26 :  
27 :  
28 :  
29 :  
30 :  
31 :  
'''

if __name__ == '__main__':
    main()