
#!/usr/bin/python
#This script was written by Darren Tapp and optimized by thephez
from decimal import Decimal
from math import log
from math import factorial as fac
from math import log1p
from math import exp
def binom(x, y):
try:
binom = fac(x) // fac(y) // fac(x  y)
except ValueError:
binom = 0
return binom
###This function takes inputs and outputs the probability
#of sucess in one trial
#pcalc is short for probability calculation
def pcalc(masternodes,quorumsize,attacksuccess,Byznodes):
SampleSpace = binom(masternodes,quorumsize)
pctemp=0
for x in range(attacksuccess, quorumsize+1):
pctemp = pctemp + binom(Byznodes,x)*binom(masternodesByznodes,quorumsizex)
#at this junctiure the answer is pctemp/SampleSpace
#but that will produce an overflow error. We use logarithims to
#calculate this value
return 10 ** (log(pctemp,10) log(SampleSpace,10))
def DekaYear(probability):
trials = 2*365*10
return 1exp(trials * log1p(probability))
#Control of Quorum
Byz = 2473
print pcalc(5000,400,240,Byz)
print DekaYear(pcalc(5000,400,240,Byz))
#Withold Chainlock
Byz = 1515
print pcalc(5000,400,161,Byz)
print DekaYear(pcalc(5000,400,161,Byz))
