Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: crafty question !! (to bob mainly)

Author: pavel

Date: 11:33:13 07/08/00

Go up one level in this thread


On July 07, 2000 at 15:23:44, Robert Hyatt wrote:

>On July 07, 2000 at 12:33:10, pavel wrote:
>
>>about position.lrn
>>
>>
>><snip>
>>
>>Crafty now has a permanent hash table that is kept from game
>>to  game. A position gets into this hash table when a search
>>value is significantly lower than the last search value. The
>>permanent hash table can hold up to 65536 positions. Once it
>>fills up, the positions are replaced on a FIFO basis, always
>>keeping the most recent 64K entries. Each time Crafty starts
>>a search, the positions  and  scores  from  this  table  are
>>stuffed into the normal transposition table, and used during
>>the search just like any other table entry.
>>
>>from the crafty ftp site (under crafty.doc)
>>
>>so it means that the position.lrn file doesnt get larger than 64000 entries. ;(.
>>and its a default setting.
>>why is it done ? I mean why is it restricted to only 64k?
>>Is it possible to make it infinite? ( no size restriction)
>>Is there a certain code that needs to be changed to overcome this problem,
>>I would graetly appreciate your help. :)
>>thanks
>>Pavel
>
>
>This is not intended to be 'permanent'.  Think about the casual user...  the
>position.bin file would grow and grow, and eventually reach the size of the
>_real_ hash table.  Now you have a _big_ problem as all the hash entries would
>be marked 'never overwrite'...
>
>You can easily modify LearnPosition() (in learn.c) to increase this limit.  I
>don't think it will help a thing...


there must be a good reason you implimented this feature (learning feature), If
it wont help a thing then why would you implement such feature?
I am guessing that you did such thing mainly for people like me who learn from
your source codes (as an standard example). but is it the only reason?
also are there any other more_effective learning feature that can be implimented
other than the one you are using.
thanks
Pavel



This page took 0 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.