RE: [computer-go] Pseudo liberties: Detect 2 unique liberties?

2009-04-07 Thread David Fotland
Yes, I walk both chains looking for duplicates. This is quite fast if done efficiently, since group merging is rare enough. I found keeping the liberty arrays to be slower since they are big, so there is more copy overhead in the UCT tree, and they are not cache friendly. David -Original

Re: [computer-go] Pseudo liberties: Detect 2 unique liberties?

2009-04-07 Thread Łukasz Lew
Thanks. What about linked lists? They seem to be both compact and fast to merge and detect duplicates. Why have you abandoned them? Lukasz On Tue, Apr 7, 2009 at 17:42, David Fotland fotl...@smart-games.com wrote: Yes, I walk both chains looking for duplicates.  This is quite fast if done

Re: [computer-go] Pseudo liberties: Detect 2 unique liberties?

2009-04-07 Thread Colin Kern
On Tue, Apr 7, 2009 at 12:33 PM, Łukasz Lew lukasz@gmail.com wrote: Thanks. What about linked lists? They seem to be both compact and fast to merge and detect duplicates. Why have you abandoned them? Lukasz Or a Hash Set, which has constant time insert, delete, contains, and size

[OT] Re: [computer-go] Pseudo liberties: Detect 2 unique liberties?

2009-04-07 Thread Jason House
This reminds me of a related question I had a while back. In a single MCTS/UCT search node, how do people store the children? Does a node contain summaries of all their children, or just pointers to the children? Pure pointers are simple but requires allocating many more objects,

[computer-go] Fast ways to evaluate program strength.

2009-04-07 Thread Łukasz Lew
Hi, I was wondering what are the good (fast/accurate) ways of evaluating program strength. The most accurate one is to play many games against gnugo or on KGS. But it is quite slow as many games are needed. Another one is to have set of labeled positions (win/loss) and make your program predict

Re: [computer-go] Pseudo liberties: Detect 2 unique liberties?

2009-04-07 Thread Adriaan van Kessel
computer-go-boun...@computer-go.org wrote on 07-04-2009 18:33:34: Thanks. What about linked lists? They seem to be both compact and fast to merge and detect duplicates. Why have you abandoned them? Linked lists have a terrible cache behaviour: every pointer (or index) dereference has a nearly

Re: [computer-go] Fast ways to evaluate program strength.

2009-04-07 Thread Petri Pitkänen
Predicting pro-moves has very low correlation to strength. I think it is next to useless. No experience but I think in this respect traditional programs probably are better but certainly lose in strength. Cooperation of moves is what matter not single moves. Could be hard to come up with

Re: [computer-go] Fast ways to evaluate program strength.

2009-04-07 Thread Jay Scott
Łukasz Lew lukasz@gmail.com: Another one is to have set of labeled positions (win/loss) and make your program predict the labels. (This is what MoGo guys did) It is much faster. But how well it is correlated with the true strength? I think it could be good if the set of positions is

Re: [computer-go] Fast ways to evaluate program strength.

2009-04-07 Thread terry mcintyre
From: Łukasz Lew lukasz@gmail.com I was wondering what are the good (fast/accurate) ways of evaluating program strength. The most accurate one is to play many games against gnugo or on KGS. But it is quite slow as many games are needed. Another one is to have set of labeled positions

Re: [computer-go] Fast ways to evaluate program strength.

2009-04-07 Thread Łukasz Lew
Another idea is to try to predict moves in a set of (pro) games. Is the prediction rate well correlated with program strength? No, very poorly correlated. I think that's well known. It is well known that systems created for pro move prediction using no search like MoyoGo, similat Microsoft's

Re: [computer-go] Fast ways to evaluate program strength.

2009-04-07 Thread Michael Williams
Łukasz Lew wrote: I would like to rephrase my question: Let's measure prediction of pro moves of a whole engine while modifying heavy playouts / MCTS in the engine. How well might it work? Probably not well. Because what matters is not how often you play strong moves, but how often you avoid

Re: [computer-go] Fast ways to evaluate program strength.

2009-04-07 Thread steve uurtamo
otherwise pair-go wouldn't be as funny to watch. s. On Tue, Apr 7, 2009 at 8:05 PM, Michael Williams michaelwilliam...@gmail.com wrote: Łukasz Lew wrote: I would like to rephrase my question: Let's measure prediction of pro moves of a whole engine while modifying heavy playouts / MCTS in

Re: [computer-go] Fast ways to evaluate program strength.

2009-04-07 Thread terry mcintyre
Amen to that. When using positions to judge the strength of a program, one would need to test not just one pro move, but a sequence of plays -- including some which don't appear in pro games. A pro knows how to deal decisively not only with the optimal plays of other pros, but also with