* Elias Gamma & Delta Codes * Golomb code

elias.py

#!/usr/bin/python

from math import log,ceil

log2 = lambda x: log(x,2)



def binary(x,l=1):
	fmt = '{0:0%db}' % l
	return fmt.format(x)

def unary(x):
	return x*'1'+'0'

def elias_generic(lencoding, x):
	if x == 0: return '0'
	
	l = 1+int(log2(x))
	a = x - 2**(int(log2(x)))
	
	k = int(log2(x))

	return lencoding(l) + binary(a,k)
	
def golomb(b, x):
	q = int((x) / b)
	r = int((x) % b)
	
	l = int(ceil(log2(b)))
	#print q,r,l

	return unary(q) + binary(r, l)
	

def elias_gamma(x):
	return elias_generic(unary, x)

def elias_delta(x):
	return elias_generic(elias_gamma,x)
	
for i in range(11):	
	print "%5d: %-10s : %-10s : %-10s" %(i, elias_gamma(i),elias_delta(i), golomb(3,i))