How to calculate Gregory series and the error with math.pi

Question

I need help with my code. I want to write a code that can calculate the error of "math.pi and pi using Gregory series". The range of error is 1.0E-1~1.0E-8. Here is my code:

import math
EPSILON=0.1
def ans(terms):
    result=0.0
    for n in range(terms):
        result+=(-1.0)**n/(2.0*n+1.0)
    return 4*result
    if abs(pi-ans)<=EPSILON:
        print n,ans,abs(pi-ans)
    else:
        print("out of different")

I can get the ans, like ans(60) >>> 3.1249271439289967, but I can't get the output of print n,ans,abs(pi-ans), what's wrong with my code?

Answer 1

It's because your print statements are indented and it makes them part of your ans() function. Your code has several other errors

• you can't use just pi but should use math.pi
• you call ans in your print statement without using argument

Your code should look like this :

import math
EPSILON=0.1
def ans(terms):
    result=0.0
    for n in range(terms):
        result+=(-1.0)**n/(2.0*n+1.0)

    return 4*result

n = 60
res = ans(n)
if abs(math.pi-res) <= EPSILON:
    print n,res,abs(math.pi-res)
else:
    print("out of different")