Re: [Bug-gnubg] [Q] Adding noise to evaluations

[Joern Thyssen]

On Tue, Dec 02, 2003 at 08:54:37PM -0700, Thomas Hauk wrote
> Can someone explain to me how the noise setting works, for evaluations?
> 
> My supervisor wanted me to add noise to the evaluations, at which point I 
> told him it was already built into the code. His concern is that the 
> method in which gnubg generates that noise is reproduceable.

gnubg can introduce both deterministic and non-deterministic noise.

The parameters rNoise and fDeterministic in the evalcontext controls it.
I didn't implement it, so I don't know the exact math behind it. You
should check the routine Noise in eval.c. 

For the deterministic noise gnubg uses the current board as input to
some algorithm involving an MD5 checksum. This way you'll get the same
noise for the same position always.

The non-deterministic noise uses a Box-Müller transform.

Jørn

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