Re: computer-go: Pattern matching

[David Fotland <fotland@xxxxxxxxxxxxxxx>]

Many programs use a bitmap+attributes approach.  Many Faces, Wilcox's
Ego, Goliath are examples.  Others code patterns in a pattern description
language.  Nemesis worked this way I think.  Martin uses a string description
that he will have to describe.  I never understood the details.

Bitmaps come is a variety of sizes.  Some use 32 bits, arranged as 5x5, or
5x5 plus a few extra points.  Goliath used 5x5 or two combined to make 5x10.
Many Faces uses 3 bitmaps of 64 bits each (8x8).  I think Stone used
11x11 patterns in 128 bits.  Programs vary in the states that can be
represented.  With 2 bits per point, they can represent black, white, empty,
and don't care.  I use 3 bits per point, to represent black, white, empty,
don't care, black or empty, white or empty, and black or white.  Attributes
associated with the pattern can refer to group strength, liberty count, or 
tactical status or stones in the group.  I indicate if the pattern is
in a corner, along an edge, or anywhere.

David


At 01:34 PM 10/28/99 +0200, you wrote:
>Hi everybody, is there any survey available about the different
>pattern-matching algorithms used in computer go? Do
>people use standard algorithms or do they take advantage of the
>specific behavior of a go game?
>
>cRil
>
>