#!/usr/bin/env python
import sys
import os
import math


def f1(x):
        return x * x

def f2(x):
        return ((x + .003) * .28) / 6.0

def f3(x):
        return x - .0008

def f4(x):
        return x * .81

# These can be anything
WANTED_1 = 6.8
WANTED_2 = 0.004
WANTED_3 = 1.0
WANTED_4 = 0.23851

if __name__ == '__main__':

    i = .5

    error = 10000.0

    numIters = 0

    while abs(error) > .000001:

        x1 = f1(i)
        x2 = f2(i)
        x3 = f3(i)
        x4 = f4(i)

        error = ( (abs(x1) - WANTED_1) + ( abs(x2) - WANTED_2 ) + ( abs(x3) - WANTED_3) + ( abs(x4) - WANTED_4 ) )
        error /= 4.0

        if error > 0:
            i -= .0000003
        else:
            i += .0000005

        numIters += 1

        #print ( "Error is: %.7f" %( error, ))

    print ( "Found best error of %.7f at x=%.7f after %d iterations" %( error, i, numIters ) )