[computer-go] Making Java much faster

[Wodzu]

----- Original Message ----- 
From: "David Doshay" <ddoshay at mac.com>
To: "computer-go" <computer-go at computer-go.org>
Sent: Thursday, November 30, 2006 11:44 PM
Subject: Re: [computer-go] Making Java much faster


>I have been *so* tempted to either ignore this thread or rename it ...
>
> On 30, Nov 2006, at 10:36 AM, Wodzu wrote:
>
>> i think speed is one of most important things beacuse it affects
>> strength of the program ;) (if the time for move is restricted)
>> anyway, chosing a proper (fastest) algorithm has crucial meaning  and
>> other things like language, used data structures and so on,  have less
>> meaning in improving speed.
>> thats my opinion, regards.
>
> This is not my experience at all.
>
> SlugGo was first written by a graduate student with data structures  that
> made sense to them, but not to me. I rewrote it to use  completely
> different data structures but with exactly the same  algorithm. It took
> less than half the time to run, and play was at  exactly the same level
> because it was move for move identical. Data  structures can have
> tremendous effect upon speed.

If you think about linked-lists, hash tables, priority queues as a data
structures than you ofourse have right.
However those strutures are realized by certain algorithms on their
implementation level. I shoul dbe more precise because I meant data typers
or primitive data structures like arrays.


>
> Also, my data shows that if I doubled the time allowed for playing,  thus
> "using" the time gained from faster execution for doing deeper  lookahead,
> the results did not improve, but actually got worse.
I've also noticed that when i run my engine to play itself on different
depth level.
The "deeper" player sometimes was defeated by his opponent with lesser depth
analysis. I guess he wasn't able to fidna good move because of the horizon 
effect.
Although I think when you run your engine with some more depth it will vipe
out its opponent from board;)

Regards,

Wodzu