global s;
s=0;
y0=[ 0.01 0.01 ]';
for j=1:1000  
   options=odeset('AbsTol',1e-12);
   [t,y]=ode45('duffingp',[0,1],y0, options);
 [m,n]=size(y);
 y0=y(m,:)';
figure(1);
axis([-2 2 -2 2]);
hold on;
plot(y(:,1),y(:,2),'r-', 'EraseMode','none' );
pause(0.1)
plot(y(:,1),y(:,2),'b-', 'EraseMode','none' );
drawnow
s=s+1;
end