exercise 7.3 - test_square_root

"""===========================

exercise 7.3

==========================="""

import math

def approx_equal(a, b, limit):

    if abs(a-b) < limit:

        return True

    else:

        return False

def square_root (a):

    x = a / 2.0

    epsilon = 0.001

    while True:

        #print x

        y = (x + a/x) / 2.0

        if approx_equal (y, x, epsilon):

            break

        x = y

    return x

    

def test_square_root(a):

    ex_sqrt = square_root(a)

    py_sqrt = math.sqrt(a)

    diff = abs(ex_sqrt-py_sqrt)

    print a, ex_sqrt, py_sqrt , diff

    

test_square_root(1.0)

test_square_root(2.0)

test_square_root(3.0)