On Tue, May 13, 2008 at 4:22 PM, Carter Cheng <[EMAIL PROTECTED]> wrote: > 2) When generating random variables for the case where the "values" of > placing a stone on different points on the board are different. Are there > good ways to throw and determine which point has been selected for the next > move by the random player?
I can answer this. The best way I know of getting a random point with different weights (proportional to probabilities) for each point is to keep a sum of weights per row and a total sum of weights for the entire board. These are easy to update dynamically when an individual weight changes. In order to pick a point, start with a random number between 0 and the total sum. Go down row by row subtracting the weight of each row, until you would get a negative number. Then walk the row subtracting the weight of each point until you would get a negative number. The place where you stop is the selected point. This method may not be very robust if you use floating-point numbers to represent weights (because you can't rely on associativity of addition), but it works fine if you use an integer type. If the description is not good enough, I can write some C++ code for you. Álvaro. _______________________________________________ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
