from gmpy2 import *

from math import log

from time import time



# This test is designed to detect issues when allocating memory for large

# numbers. If it crashes and you need to work with very large numbers,

# you will need to compile GMP from scratch and try a different memory

# allocation option.







def pi(N):

    print("Computing pi to %s decimal places." % N)

    start = time()

    N = int(round(log(10,2)*N))

    sq2 = fsqrt(mpf(2, N))

    a = mpz(6) - 4*sq2

    y = sq2-1

    for k in range(0, 10000):

        xx = fsqrt(fsqrt(1-y**4))

        y = (1-xx)/(1+xx)

        anew = a*(1+y)**4 - 2**(2*k+3)*y*(1+y+y**2)

        if anew == a:

            break

        a = anew

    print("Computation took %5.2f seconds." % (time() - start))

    return 1/a



if __name__ == '__main__':

    print("Testing operations with large numbers.")

    pi(1000000)