how to calculate CFG distance? Fuming
On Tue, Jan 25, 2011 at 3:49 AM, Brian Sheppard <[email protected]> wrote: > I use CFG distance only in the tree. The playout uses the concept > "adjacent" > which is trivial to compute. > > The only distance I am concerned about is the distance to the last move, > and > there are only 4 classes: distance 1,2,3, and >3. So it is cheap. > > The advantage is in semeais. Moves at CFG distance 3 are the outside > liberties of the opponent's string. > > There was not a big difference compared to the other two heuristics. I > found > that > > - CFG is best > - max(dx, dy) + (dx + dy)/2 is second best > - Manhattan is third. > > Brian > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Jacques Basaldúa > Sent: Monday, January 24, 2011 2:41 PM > To: [email protected] > Subject: [Computer-go] Computing CFG distance in practice > > Hi, > > I got a lot of improvement recently (something you all > did long time ago) with proximity heuristics. I am using > > Manhattan distance: > d = max(dx, dy) > > and > d = max(dx, dy) + (dx + dy)/2 > > where dx = abs(ex - ox) and dy = abs(ey - oy) > > But many people report CFG distance to be superior. > > What do you do: > > a. Compute it in root. Then build a lookup table and > use the LUT during playouts and tree search. > > b. Compute the shortest path from (ox, oy) to (ex, ey) > connected by the stones on the board each time you need > to evaluate a distance. > > I don't like a because it looks inefficient as the > board changes a lot during the search. > > I don't like b because it looks computing intense > unless there is some smart idea I am missing. > > > Jacques. > > > > > > > > _______________________________________________ > Computer-go mailing list > [email protected] > http://dvandva.org/cgi-bin/mailman/listinfo/computer-go > > _______________________________________________ > Computer-go mailing list > [email protected] > http://dvandva.org/cgi-bin/mailman/listinfo/computer-go >
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