Thinking about Monte Carlo playouts

   Finished my homework panic (for this particular half of this particular half of this particular week).

   Now I am reflecting on what a Monte Carlo play-out should consist of. At the moment, each empty spot on the board that isn't a living one space eye gets a number, and then those get played out until a capture happens, at which point everyone gets a new random number. Obviously there's some extraneous work being done there.

   One optimization would be instead of redoing the whole board after a capture, simply inserting new legal moves after a capture at random locations would avoid some work.

   Another would be playing known-to-be-non-capturing moves before a capture simultaneously.

   This is somewhat motivated by Hirabot 1d 19x19 repeatedly smashing me on KGS. Also, 15,000 play-outs in under thirty seconds?! In contrast, Ayabots 1k - 1d only do 1500 play-outs and are clearly over-ranked. So my bot needs to be doing 2-3 orders of magnitude more play-outs in only 30 seconds.

Otherwise, I am doing something (at school) with Geant4. I wonder if Geant4 has something to offer my Matlab go evaluation (because mex is so dependable).

Busy studying today

   I only did the first Google Code Jam problem, too. At some point I got fed up with remembering Java syntax, which in hindsight required more preparation. Next year, Python, surely.

   This weekend is dedicated to schoolwork.

   A scintillator like potassium iodide crystals will somewhat get you visible light from higher energy gamma rays, which is easier to find. My use of the term 'x-rays' might be erroneous.

Reading SGFs too

(I'm on holiday)

   Irritatingly, the move numbers I am using are MATLAB figure text. If I 'print the figure to a file', all the text becomes my current font color. If I write the board image as an image, I lose the text. I will argue that I wanted the gif to be small and in that case the numbers don't make sense. 

   The game is Rin Kaiho vs Fujisawa Hideyuki 1982.

Serializing to SGF

At the moment my bots produce stacks of boards (aimed at easily displaying the progress of a game). Also I speculate that 19^2 is small enough that passing them around will not matter a lot.

But the go world runs on Smart Game Format. I really don't write files of arbitrary strings in MATLAB a lot.


function [] = WriteSgfOfBoardStack( boardStack, fileName)
%WriteSgfOfBoardStack Writes an array of boards to an SGF.
%   V. http://www.red-bean.com/sgf/sgf4.html

LETTERS = {'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's','t'};

sgfText = '(;FF[4](;';

for i = 2 : length(boardStack);
    changesBoard = boardStack(:,:,i)-boardStack(:,:,i-1);
    changesBoard(changesBoard<0)=0;
   
    if mod(i-1,2) == 0
        C = 'W';
    else
        C = 'B';
    end
   
    [row, col] = find(changesBoard);
   
    moveString = strcat(';', C, '[',LETTERS{col},LETTERS{row},']');
   
    sgfText = strcat(sgfText, moveString);
end

sgfText = strcat(sgfText, '))');

f = fopen(fileName, 'w+');

fprintf(f,sgfText);

fclose(f);

end

Why is there the word imaging in the blog address

Also: Reveling in my own beautiful graphics

First Steps Heuristics

This 'bot' picks next moves by following very simple rules and starts with 1 and 2 on the board.

1. For each player, convolve kernels representing 1:3 space jumps and knights moves. (This is the interesting step).
2. Exclude the first and second line and contact moves.
3. Exclude moves only one player is interested in
4. Randomly select from the remaining moves

Go exchanges can be thought of as combinations of mainly jumps and knights' moves ('haengma' : This link could not be useful for anyone). Being able to express these different moves facilitates actual decision making, later.