1639.sagews

# Madison Schaeffer & Evan Raskin

import numpy as np

x = np.array([0.,1.,2.,3.,4.])
S = np.array([500.,400.,200.,50.,0.])
b = np.array([0.,2.,3.,1.,0.])

def lx(S):
    return S/S[0]
    
R0 = np.sum(lx(S)*b)
G = np.sum(x*lx(S)*b)/R0

print lx(S)
print R0
print G

sign = ['+']

RVALUE = log(R0)/G
print RVALUE

refined_r = [RVALUE] 

def refine():
    global sign
    global refined_r
    if abs(1 - np.sum(lx(S)*b*exp(-refined_r[-1]*x))) > .001:
        if (1 - np.sum(lx(S)*b*exp(-refined_r[-1]*x))) > 0:
            sign.append('-')
            if sign[-2] != sign[-1]:
                binary()
            else:
                decrease_me()
        else:
            sign.append('+')
            if sign[-2] != sign[-1]:
                binary()
            else:
                increase_me()
    else:
        print refined_r[-1], 'LIZARD!'


def decrease_me():
    refined_r.append(refined_r[-1]*.9)
    refine()

def increase_me():
    refined_r.append(refined_r[-1]*1.1)
    refine()
    
def binary():
    refined_r.append((refined_r[-1] + refined_r[-2])/2)
    refine()
    
refine()

[ 1. 0.8 0.4 0.1 0. ] 2.9 1.48275862069 0.7180607296 0.776744726549 LIZARD!

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