added matlab version

README.md

@@ -13,9 +13,8 @@ settings I could manage. The C was compiled with -O2 and the
 Java with -O. The JavaScript was run with the d8 shell of
 the v8 interpreter [1], with the Java-based rhino
 interpreter shell [2], and with the js shell of SpiderMonkey
-[3]. I don't have access to Matlab; I would be curious to
-find out how its performance compares with Octave's on this
-benchmark.
+[3]. The Matlab version [4] was run on a different machine,
+because I had access to Matlab there.
 
 Timings on my home machine (2GHz Intel Core 2 Quad Q9300)
 are as follows:
@@ -27,6 +26,7 @@ are as follows:
     JavaScript [3]:  3.0s
     Python:          8.3s
     Nickle:          14s
+    Matlab [4]:      15s
     Octave:          3.5m
 
 Yes, Octave is 4000x slower than C on this benchmark!

matlab/gamevalue.m

@@ -0,0 +1,72 @@
+% Copyright © 2012 Bart Massey
+% [This program is licensed under the "MIT License"]
+% Please see the file COPYING in the source
+% distribution of this software for license terms.
+
+% Perfect Tic-Tac-Toe player in Matlab / Octave
+
+
+% Returns the value of the game to the
+% side on move if the game is over, or
+% -2 if the game is still in progress.
+function v = gamevalue(onmove, S)
+  % first scan for wins
+  for side = [-onmove, onmove]
+    v = side * onmove;
+    % scan for diagonal
+    n = 0;
+    for d = 1:3
+      if S(d, d) == side
+        n = n + 1;
+      end
+    end
+    if n == 3
+      return
+    end
+    % scan for opposite diagonal
+    n = 0;
+    for d = 1:3
+      if S(d, 4 - d) == side
+        n = n + 1;
+      end
+    end  
+    if n == 3
+      return
+    end
+    % scan for rows
+    for r = 1:3
+      n = 0;
+      for c = 1:3
+        if S(r, c) == side
+          n = n + 1;
+        end
+      end  
+      if n == 3
+        return
+      end
+    end
+    % scan for cols
+    for c = 1:3
+      n = 0;
+      for r = 1:3
+        if S(r, c) == side
+          n = n + 1;
+        end
+      end
+      if n == 3
+        return
+      end
+    end
+  end
+  % scan for blanks
+  v = -2;   % game not over
+  for r = 1:3
+    for c = 1:3
+      if S(r, c) == 0
+        return
+      end
+    end
+  end
+  % game is a draw
+  v = 0;
+end

matlab/negamax.m

@@ -0,0 +1,44 @@
+% Copyright ?? 2012 Bart Massey
+% [This program is licensed under the "MIT License"]
+% Please see the file COPYING in the source
+% distribution of this software for license terms.
+
+% Perfect Tic-Tac-Toe player in Matlab / Octave
+
+% Pseudocode:
+
+% To calculate the negamax value of a position s:
+%    If s is a final state (game over)
+%        return the value of s to the side on move
+%    v <- -1
+%    for each legal move m in s
+%       s' <- m(s)
+%       v' <- -negamax(s')
+%       if v' > v
+%           v <- v'
+%    return v
+
+function v = negamax(onmove, S)
+  % printf("tomove: %d\n", onmove);
+  % S
+  v = gamevalue(onmove, S);
+  if v ~= -2   % game is over
+    % printf("result: *%d\n", v);
+    return
+  end
+  v = -1;
+  for r = 1:3
+    for c = 1:3
+      if S(r, c) == 0
+        % printf("examining %d %d\n", r, c);
+        S(r, c) = onmove;
+        v0 = -negamax(-onmove, S);
+        if (v0 > v)
+          v = v0;
+        end
+        S(r, c) = 0;
+      end
+    end
+  end
+  % printf("result: %d\n", v);
+end

matlab/ttt.m

@@ -0,0 +1,8 @@
+% Copyright ?? 2012 Bart Massey
+% [This program is licensed under the "MIT License"]
+% Please see the file COPYING in the source
+% distribution of this software for license terms.
+
+% Perfect Tic-Tac-Toe player in Matlab / Octave
+
+negamax(1, [0 0 0; 0 0 0; 0 0 0])