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Subject: Re: How do you insure that Hash Table entries are correct?

Author: Larry Griffiths

Date: 23:46:34 09/16/00

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On September 16, 2000 at 23:54:19, Robert Hyatt wrote:

>
>what random() function are you using?   IE stock random() doesn't have any
>arguments.  If it is a seed, there are known good and bad seeds.  In almost
>_all_ cases, you want the seed to be odd, and usually prime.

I tried using my compilers rand() function but it was only generating
random numbers from 0 to 0x7fff.

I ran 78 positions from the BWTC suite
and got over 10,000 mis-matches using my 64-bit hash keys.
I looked at my smallboards and they usually differ by a piece missing or in a
different position.  My Piece table does not have zero or duplicate entries
and the random numbers in the piece table look good.
I built hashkeys using the two different smallboards and they do indeed
generate the same hashkeys.

Maybe my hashkeys should be prime numbers?

I will play around with random some more and see if it changes my mismatch
rate.

Thanks Bob.

Larry.



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