Python: Calculate sine/cosine with a precision of up to 1 million digits

Question

Question is pretty self-explanatory. I\'ve seen a couple of examples for pi but not for trigo functions. Maybe one could use a Taylor series as done here but I\'m not entire

Answer 1

Try this

import math
from decimal import *


def sin_taylor(x, decimals):
    p = 0
    getcontext().prec = decimals
    for n in range(decimals):
        p += Decimal(((-1)**n)*(x**(2*n+1)))/(Decimal(math.factorial(2*n+1)))
    return p


def cos_taylor(x, decimals):
    p = 0
    getcontext().prec = decimals
    for n in range(decimals):
        p += Decimal(((-1)**n)*(x**(2*n)))/(Decimal(math.factorial(2*n)))
    return p

if __name__ == "__main__":
    ang = 0.1
    decimals = 1000000
    print 'sin:', sin_taylor(ang, decimals)
    print 'cos:', cos_taylor(ang, decimals)