
 A = [1 2; 0 1];                        % the matrix
 plot([-2 2],[0 0])
 hold on
 plot([0 0],[-2 2])
 for j=1:24,                            % do what follows 12 times
     ang = j*2*pi/24;                   % angle
     x = [cos(ang); sin(ang)];          % a point on the unit circle
     y = A*x;                           % transformed by A
     text(x(1),x(2),num2str(j))         % place the counter value at x
     %hold on                            % save the picture
     s = text(y(1),y(2),num2str(j));    % place the counter value at y
     set(s,'color','r','fontsize',8)                 % paint that last value red
 end
 hold off
 axis equal
 %hold off                               % let go of the picture
 %axis([-2.5 2.5 -2.5 2.5])              % fiddle with the axes