function abm_wolfram

gr_sz = 100; % grid size
iterations = 100;  

% define initial state
x = round(rand(1,gr_sz));

for it = 1:iterations

  % interior
  for i = 2:(gr_sz-1) 
    a = x(it,i-1) * 4 + x(it,i) * 2 + x(it,i+1);
    if ( a == 0 ) || ( a == 2 ) || ( a == 5 ) || ( a == 7 )
      x(it+1,i) = 1;
    else
      x(it+1,i) = 0;
    end
  end
  
  x(it+1,1) = 1;   % left boundary
  
  x(it+1,gr_sz) = 1; % right boundary
  
end

% pcolor does not plot the last row for some reason
% so we copy the last row twice:
x(:,gr_sz+1) = x(:,gr_sz);

pcolor( x ); % surf( x ); view(0,90);
%axis([ 1 gr_sz 1 iterations ]);
colormap bone; % gray bone;
shading flat; % flat faceted interp

xlabel('grid space');
ylabel('time')