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#1 2006-04-24 13:04:00
- ryos
- Power Member
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Pi, the long way around
The blogger "ridiculous fish" has implemented a very novel approach to cutting out comment spam (and much better than the "distorted image" method). I thought it was both interesting and cool. Have a look:
http://ridiculousfish.com/blog/?p=23
Last edited by ryos (2006-04-24 13:04:19)
El que pega primero pega dos veces.
#2 2006-04-24 19:33:02
- MathsIsFun
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Re: Pi, the long way around
So far they have:
* 1359 / 2475 pairs were relatively prime.
* pi is approximately 3.30562434615
"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman
#3 2006-04-24 23:08:56
- krassi_holmz
- Real Member
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Re: Pi, the long way around
Pretty interesting.
IPBLE: Increasing Performance By Lowering Expectations.
#4 2006-04-24 23:35:19
- krassi_holmz
- Real Member
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Re: Pi, the long way around
Here's a Mathematica fuction which makes n tests with numbers less than b:
Code:
PPr[n_, b_] :=
(
c = 0;
Do[If[GCD[Random[Integer, {1, b}], Random[Integer, {1, b}]] == 1, c++;], {i, 1, n}];
c/n
)6/pi^2=0.607927
As you see, this method is unusable, because for approximately 3 digits of 6/pi^2 you need >10^6 tests.
IPBLE: Increasing Performance By Lowering Expectations.
#5 2006-04-25 00:19:38
- Patrick
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Re: Pi, the long way around
well, one million comments, that's not that much 
He's just trying to make a laugh of spam 
(but ruining his fun is great too 
)
#6 2006-04-25 10:04:09
- MathsIsFun
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Re: Pi, the long way around
Good work, krassi!
Another (of the many) ways to calculate π would be to pick a random coordinate in a square, then see if it falls within the inscribed circle (using x²+y²=r²).
"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman