matlab 点坐标连续绘图不抹去

 shg
clf reset
set(gcf,'color','white','menubar','none', ...
   'numbertitle','off','name','Fractal Fern')
x = [.5; .5];
h = plot(x(1),x(2),'.');
darkgreen = [0 2/3 0];
set(h,'markersize',10,'color',darkgreen,'erasemode','none');
drawnow

x=[-.5;.5]+x;
set(h,'xdata',x(1),'ydata',x(2));
drawnow

x=[-.5;.5];
set(h,'xdata',x(1),'ydata',x(2));
drawnow