From: kv07@IASTATE.EDU (Warren Vonroeschlaub)
Subject: Re: AWESOME computer program (Populus)
Reply-To: kv07@IASTATE.EDU (Warren Vonroeschlaub)
Organization: Ministry of Silly Walks
Date: Wed, 11 Nov 1992 23:58:16 GMT

In article <1992Nov11.125743.1085@city.cs>, lionel@cs.city.ac.uk (Lionel Tun)
writes:
> In article <MAGUIRE.92Nov10155811@signal.clarkson.edu>
maguire@sun.soe.clarkson.edu (Bill Maguire) writes:
> >Here's something you could do with this game.  Take a set of these
> >games, each with different random weights.  Have a little tournament
> >then throw out the games that did the worst.  Duplicate the remaining
> >games and modify the weights in the duplicates by a small random
> >amount.  Repeat until you get bored.  Think that final set of games is
> >any better than the first batch Lionel?
> 
> A number of people have pointed out this sort of use 
> of `randomness' in the design of a program. But please note that  
> the program has been specially designed in this way. The use of
> randomness here is very specific and very tightly controlled. It
> is being used as part of the _design_ process.

  Ha.  This is actually a program being run in the chess programming language. 
It could easily be compiled or ported to ROM if you want.  It could probably
(and probably already has) be put onto a chip and run as a machine language.

>>Well even if you don't, the important thing to understand is that
>>different weights produce different behavior.  Some values of
>>weights will produce better games than others.
>>
>>I'm sure you can easily see that if the memory location holding the
>>number of moves to look ahead is increased then, although the computer
>>game will be slower, the program will be better at chess.
>>
>>If the program is using a polynomial heuristic, by modifying one of the
>>coefficients you just might make the program play better.
> 
> This is more like it, the sort of random mutation I am talking
> about. Lets say the chess program is 1M (approx 1 million bytes or
> 8 million bits).

  Well, the original Sargon was under 8K, but I'm nitpicking.

> You randomly change a few bits. Your claim is
> that you may by chance change a variable such as `number of
> moves ahead' or `a coefficient of some sort'. Do you really
> think that the program will play better chess? I am talking
> about a _well designed_ chess program which has _already_
> been finely tuned. In evospeak you might say an organism that
> has become well adapted to its environment.

  Sure.  There are some things humans just don't do well.  One of them is
finding the perfect balance of 50,000 variables.  The rest of your post kind of
ignored this, so I zapped it.

> >I think its time for you to eat your flat cap.
> 
> Haha. Thou speakest too soon.

  Show us one reason why changing the data structures in a Chess program,
competeing thousands of different mutants against each other, and repeating
won't work?  Especially when it has been done.

  If I get some free time I'll write up a simple demo showing this works.

 |  __L__
-|-  ___  Warren Kurt vonRoeschlaub
 |  | o | kv07@iastate.edu
 |/ `---' Iowa State University
/|   ___  Math Department
 |  |___| 400 Carver Hall
 |  |___| Ames, IA  50011
 J  _____
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