Thank you Don and Sylvain. I now understand this issue completely. One more question. Line 23 states: for i:=node.size()-2 to 0 do. The leaf node should be stored in node[node.size()-1], so why do we start at node.size()-2? Is it not necessary to update the value of the leaf node?
-----Original Message----- From: Don Dailey <[EMAIL PROTECTED]> To: Dmitry Kamenetsky <[EMAIL PROTECTED]>, computer-go <computer-go@computer-go.org> Date: Wed, 21 Feb 2007 12:54:43 -0500 Subject: Re: Re[2]: [computer-go] UCT vs MC > > On Wed, 2007-02-21 at 16:56 +0300, Dmitry Kamenetsky wrote: > > Thank you for your answer. However, I am even more confused now. I > > understand that "-" is for negamax, but I don't understand why it > > became "1-". I am trying to implement your algorithm and I just want > > to know what lines 7, 16 and 26 should be? > > I'm not sure this is what you are looking for, but in negamax, scores > can be negative or positive. The scores are always adjusted so that > you can view positive numbers as "good" and negative as "bad" from the > point of view you are referencing. So to get the score from the > "other" > point of view you simple negate it. > > But in UCT, we don't deal with negative numbers. A score is between > 0 and 1, so 0.001 is almost losing and 0.999 is almost winning for > example. > > To change 0.99 to the other players point of view in this system, where > scores must be between 0 and 1, you must negate it and add 1. So 0.99 > becomes: 1 - 0.99 = 0.01 > > I hope that is what you are asking about and that this explains it. > > - Don > > _______________________________________________ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
