[hezhg]

t=0i/100:2*pi;
y=sin(t);
plot(t,y);
h=line('color',[1 0 0],'marker','.','markersize',40,'erasemode','xor');
n=length(t);
for i=1:n;
set(h,'xdata',t(i),'ydata',y(i));
drawnow;
pause(0.005)
end