Pi Calculation Code Golf [closed]

Question

The Challenge

You must calculate pi in the shortest length you can. Any language is welcome to join and you can use any formula to calculate pi. It must be able to calculate pi to at least 5 decimal places. Shortest, would be measured in characters. Competition lasts for 48 hours. Begin.

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^{Note: This similar question states that PI must be calculated using the series 4 * (1 – 1/3 + 1/5 – 1/7 + …). This question does not have this restriction, and in fact a lot of answers here (including the most likely to win) would be invalid in that other question. So, this is not a duplicate.}

Answer 1

Python 3.x - 123

Sadly this has very little precision... giving only 1-2 decimal places correct.

Anyway this is a fun method of calculating pi.

import random
R = lambda: random.uniform(-1,1)
print(sum(1 for _ in range(10**6) if abs(R() + R()*1j) < 1)*4/10**6)

Answer 2

Ruby 8

-0.0.arg 

Output takes 2 more chars:

p -0.0.arg  # => 3.141592653589793

Answer 3

Python 3, 91 (with display), 82 (just calculation)

This knows that Pi is 3, then it uses the Nilakantha method to calculate Pi accurately to 6 decimal places.

p,n,s=3,2,1
while s<99:
 n,s,z=n+2,s+1,4/(n*(n+1)*(n+2))
 if s%2<1:p+=z
 else:p-=z
print(p)

It starts with the humorous 3,2,1, but also with the rather distasteful p,n,s...

Output

3.141592 395970107
The space is to separate the correct output from the incorrect.

Answer 4

Java, 55

class P{static{System.out.print(Math.toRadians(180));}}

Hooray for static blocks ^_^

Answer 5

bc, 8 characters

Solution :

3+.14159

Usage :

$ bc <<< "3+.14159"
3.14159
$ 

Answer 6

Python, 27 chars

print "%.5f"%(355.0/113.0)

Answer 7

Matlab or Octave

0+pi

So short stackexchange won't let me post it without this. The output:

octave:5> 0+pi
ans =  3.14159265358979