PI calculated by hand. If this doesn't blow your mind nothing will.

What is on Your Mind?
1

This came to my attention very recently...
I have put it here as a fun item not related to UNIX in any way...

Chudnovsky algorithm - Wikipedia

WOW!
And a great, light hearted 16 minute video about it:

Calculating by hand: the Chudnovsky algorithm - YouTube

Enjoy...

1 Like
2

Fixed the title. Nice topic!

3

I most like the d = 163 assumption - the rest is beyond me, I'm afraid.

4

Hi...
(Apologies for any typos.)
I decided to try the Python code supplied in the wiki URL...
No alteration to the code, Python 2.7.10 - OSX default, and Python 3.5.2 on the same machine, both are old.
OSX 10.13.3, default bash terminal:

Last login: Mon Mar 19 13:26:13 on ttys000
AMIGA:amiga~> cd Desktop/Code/Python
AMIGA:amiga~/Desktop/Code/Python> python2.7 chudnovsky_pi.py
PI(maxK=70 iterations, gc().prec=1008, disp=80 digits) =
3.141592653589793238462643383279502884197169399375105820974944592307816406286208

For greater precision and more digits (takes a few extra seconds) - Try
Pi = PI(317,4501,4500)
Pi = PI(353,5022,5020)
AMIGA:amiga~/Desktop/Code/Python> python3.5 chudnovsky_pi.py
PI(maxK=70 iterations, gc().prec=1008, disp=80 digits) =
3.141592653589793238462643383279502884197169399375105820974944592307816406816734

For greater precision and more digits (takes a few extra seconds) - Try
Pi = PI(317,4501,4500)
Pi = PI(353,5022,5020)
AMIGA:amiga~/Desktop/Code/Python> _

Note the last 6 digits!
I have no idea why they should be different.
Is this a bug or just a limitation of version 2.7.x, assuming 3.5.x is correct?
Although I think Python 2.7.x is being dropped in 2020 so subtleties like this are being ignored?