I prune nodes with few visits. Most of the nodes in the tree have very few visits, so there is usually lots of opportunity for pruning.
David > -----Original Message----- > From: computer-go-boun...@computer-go.org [mailto:computer-go- > boun...@computer-go.org] On Behalf Of Isaac Deutsch > Sent: Monday, June 01, 2009 1:55 AM > To: computer-go > Subject: [computer-go] UCT tree pruning > > Hi. > > I've been thinking about pondering, and the way the tree has to be built to > support pondering. Because with pondering, the thinking time for a move can > be very big theoretically, I would like to handle automatic pruning of the > tree to avoid running out of memory. Right now I have a fixed size pool of > nodes, and I simply stop the tree from growing when I see that all nodes > are used. However I'm afraid this could hurt the performance when thinking > times are very long. > > This brings me to my question: When I see that I'm running out of memory, > which leaves/subtrees of the UCT tree should be pruned? > > -Prune moves with a low winrate and a low variance. This would favor nodes > near the root, and often lots of memory would be freed this way. However, > one has to be careful not to prune potentially good moves. > > -Prune leaf nodes with little visits that are old. This would have a small > impact on the UCT search but the memory freed is very little, meaning I > would have to do a lot of pruning. > > Another approach would be of course to just let the tree grow > indefinitely and hope that it will not use too much memory, but I'm not sure > it would work well in all situations. > > What do you do in your programs? Have you tested other approaches? Do you > think hard pruning is bad in general? > > Regards, > -ibd > -- > Nur bis 31.05.: GMX FreeDSL Komplettanschluss mit DSL 6.000 Flatrate und > Telefonanschluss nur 17,95 Euro/mtl.!* http://portal.gmx.net/de/go/dsl02 > _______________________________________________ > computer-go mailing list > computer-go@computer-go.org > http://www.computer-go.org/mailman/listinfo/computer-go/ _______________________________________________ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
