function animation()
%clf
n=201; t= linspace(0, 12*pi, n);

x = cos(t);  y = sin(t);
 
for i=1:n
  pause(.001)
  plot(x(i),y(i),'r*'); hold on
  plot([-1.5 1.5],[-1,-1]); hold off
  %grid('on')
  axis('equal'); axis([-2 2 -2 2]); 
end % end for loop



end % end function animation