Yes, I save the search state from move to move. I don't save the tree, since I don't have a DAG. I keep the depth from the start of the game, not the start of the search.
I give up when there are no nodes that area available to be overwritten. If the search is long enough, there are no nodes that can be recovered, and the UCT tree stops growing. I keep searching when there are no reusable nodes. David > -----Original Message----- > From: computer-go-boun...@computer-go.org [mailto:computer-go- > boun...@computer-go.org] On Behalf Of Peter Drake > Sent: Sunday, July 05, 2009 7:08 PM > To: computer-go > Subject: Re: [computer-go] Hash tables > > On Jul 5, 2009, at 6:01 PM, David Fotland wrote: > > > a) I don't use timestamps. I don't have a DAG. I just reuse nodes > > that > > have few visits or are old (I keep the depth from root in each node). > > Do you save the tree between turns? If so, how do you adjust the depth > from the root when a "real" move is played and one of the children of > the old root becomes the new root? Similarly, do you "clear out" all > of the nodes, so they don't look like they have many visits? > > ...or does "root" mean the beginning of the game? > > > b) By unsuccessful search, I assume you mean the linear search in > > the probe. > > I don't do a probe search, so I can't help you there. I have a strong > > aversion to doing big linear searches in performance-sensitive code :) > > I share the same aversion. Do you simply give up if the node indicated > by (zobristHash % tableSize) cannot be overwritten? > > > How big are your nodes? If you have 2 GB, they are about 15 KB > > each. That > > seems a little large. > > The machine in question has 1 GB, and I believe the nodes are around > 1K (for 9x9). That does imply that I should be able to fit around a > million of them in there, but the machine thrashes when I go from 128K > to 256K nodes. > > Peter Drake > http://www.lclark.edu/~drake/ > > _______________________________________________ > 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/
