円周率をマチンの公式を使って10000桁計算

calc-pi.py

# 出力結果は3の後ろに小数点が無いのと最後の4桁は未収束の為除いたものが正しい値

import time

def mpiarccot(x):
    base = 10 ** (10000 + 4)
    a = x
    b = 1
    pos = base // (a * b)
    s = 0
    while pos > 1:
        pos = base // (a * b)
        s += -pos if (2 & b) != 0 else pos
        a *= x * x
        b += 2
    return s

start = time.time()
pi = 4 * (4 * mpiarccot(5) - mpiarccot(239))
elapsed_time = time.time() - start
print(pi)
print(elapsed_time)