#! /usr/bin/env python
# -*- mode:python; coding:utf-8; -*-

#  Calculation of Pi using quadrature. Sequential algorithm.  While loop.
#
#  Copyright © 2008–2011 Russel Winder

import time

if __name__ == '__main__' :
  n = 10000000 # 100 times fewer due to speed issues
  delta = 1.0 / n
  startTime = time.time ( )
  sum = 0.0
  i = 1
  while i < n + 1 :
    x = ( i - 0.5 ) * delta
    sum += 1.0 / ( 1.0 + x * x )
    i += 1
  pi = 4.0 * delta * sum
  elapseTime = time.time ( ) - startTime
  print ( "==== Python Sequential While Multiply pi = " + str ( pi ) )
  print ( "==== Python Sequential While Multiply iteration count = " + str ( n ) )
  print ( "==== Python Sequential While Multiply elapse = " + str ( elapseTime ) )