Re: [gnugo-devel] anchor_in_goal for owl_attackpats.db

[Dave Denholm]

Arend Bayer <address@hidden> writes:

> On Wed, 23 Oct 2002, Trevor Morris wrote:
> 
> > http://www.public32.com/games/go/trevor_3_11.1
> >
> > - Added explicit anchor for owl_attackpats.db patterns
> >
> >
> > I duplicated a few patterns w/ different anchors.
> >
> > This explodes the size of the DFA database (about 4x !), but only
> > if the "-m" parameter is omitted.  So, this patch doesn't actually
> > cause any changes, since the -m option chooses its own anchor.
> The only disadvantage at the moment are duplicated patterns, but I think
> that is not a problem.
> 
> What worries me a little is the increase of the DFA size. I tried diabling
> your additional patterns, and still got an increase to three times the
> original size (note that there is _no_ increase without changing the mkpat
> options in the Makefile). This is probably because "-m" is more clever in
> selecting the anchor such that the spiral will be short.
> 


Possibly stupid question...

do you need to disable -m globally in order that mkpat honours your anchor
in a few patterns ?

Can -m not just be refined to take into account explicit anchors, and only apply
its own heuristic if there isn't an explicit anchor ?

Anyone looked at making -m the default anyway ?  I think I tried once, but
as usual it means reading after matching patterns happens in a different order,
and so it is hard to verify that nothing bad happens.

Having an anchor in the centre also helps the grid optimisation...



dd
-- 
address@hidden          http://www.insignia.com