CS 99

Summer 2002: Final Project                                                           08.01

The Game Of Life

---

%GameOfLife.m

size = input('Enter a size: ');

M = round( rand( size, size ) );

n = 1;

while 1

     N = neighbors( M );

     M = (~M & N == 3 ) | (M & ( N == 2 | N == 3)) | ...

          M.*~(M & ( N < 2 | N > 3 ));

     spy( M, 'b*' );

     n = n + 1;

     title(['Generation ', num2str( n )]);

     pause( 0.02 );

end

 

---

 

function [ N ] = neighbors( M )

%NEIGHBORS  Returns a matrix whose individual elements are the number of neighbors of the
%                     corresponding element in its input (0-1) matrix.

N = shiftleft(M) + shiftright(M) + shiftdown(M) + shiftup(M) + ...

          shiftdown(shiftleft(M)) + shiftup(shiftleft(M)) + shiftdown(shiftright(M)) +

...

          shiftup(shiftright(M));

  

---

function M = shiftdown( M )

%SHIFTDOWN  Returns the input matrix with its rows shifted down by one position, with wrapping.
M = M( [end 1:end-1], : );

 

---

function M = shiftup( M )

%SHIFTUP  Returns the input matrix with its rows shifted up by one position, with wrapping.
M = M( [2:end 1], : );

---

function M = shiftleft( M )

%SHIFTLEFT  Returns the input matrix with its columns shifted left by one position, with wrapping.
M = M(:, [2:end, 1]);

 

---

function M = shiftright( M )

%SHIFTRIGHT  Returns the input matrix with its columns shifted right by one position, with wrapping.

M = M(:, [end, 1:end-1]);