From: Charles Oliver Nutter <charles.nutter@...>
Date: 2009-04-30T01:20:33+09:00
Subject: Re: [QUIZ] Digits of Pi (#202)

Daniel Moore wrote:
> This week's quiz is to write a Ruby program that can compute the first
> 100,000 digits of π.

There's the impl on the benchmarks game (shootout):

http://shootout.alioth.debian.org/u32q/benchmark.php?test=pidigits&lang=ruby&id=1

But it doesn't seem fast enough to get to 100k digits in any amount of 
time I'm willing to wait for it. Here's timings for all the Ruby 
versions I have handy, calculating up to 10k digits:

(jruby time is on Java 6 server VM)

JRuby 1.3-dev:    0m47.903s
Ruby 1.9.1:       1m27.527s
Rubinius master:  2m50.545s
MacRuby 0.4:      1m9.832s
IKRuby*:          3m26.861s
Ruby 1.8.7:       1m47.887s

MacRuby 0.5-experimental crashed after only a few digits. IKRuby is 
JRuby on CLR (Mono, here) using IKVM.

Seems like we need a faster algorithm!

- Charlie