Cellular Automata in Matlab

1. Conway's life.
   The rule is:
   • Sum the 8 nearest neighbors
     
   • If the sum=2 then the state does not change
   • If the sum=3 then the state=1
   • Otherwise the state=0
     
   The code:

   x = 2:n-1;
   
   y = 2:n-1;
   
     %nearest neighbor sum
   
   sum(x,y) = cells(x,y-1) + cells(x,y+1) + ...
   
   		   cells(x-1, y) + cells(x+1,y) + ...
   
   		   cells(x-1,y-1) + cells(x-1,y+1) + ...
   
   		   cells(3:n,y-1) + cells(x+1,y+1);
   
   % The CA rule
   
   cells = (sum==3) | (sum==2 & cells);