kamogawa.py

#!/usr/bin/env python
# vim:fileencoding=utf-8
'''
a experiment for Kamogawa Equal-Distance Law
usage:
  % kamogawa.py #pairs second_pair_distance
eg.
  % kamogawa.py 10 100.0
'''
from sys import argv,stderr
from collections import defaultdict

try:
  num_pairs = int(argv[1])
  second_pair_distance = float(argv[2])
except(NameError,IndexError,ValueError):
  stderr.write('Invalid Arguments! Abort\n')
  exit(1)

pairs = []
pairs.append(0.0)
pairs.append(second_pair_distance)

for n in xrange(num_pairs-2):
  distance = 0.0
  pos = 0.0
  for i in xrange(len(pairs)-1):
    a = pairs[i]
    b = pairs[i+1]
    if abs(a - b) > distance:
      distance = abs(a - b)
      pos = min(a,b) + distance/2.0
  pairs.append(pos)
  pairs.sort()

dist_dict = defaultdict(int)
for i in xrange(len(pairs)-1):
  a = pairs[i]
  b = pairs[i+1]
  dist_dict[abs(a - b)] += 1

print('distance variations:')
for i in sorted(dist_dict.items()):
  print('%f\t%d' % i)