MATLAB仿真 让波形动起来

dt=1e-6;
T=2*1e-3;
for N=0:500;
t=N*T+(0:dt:T);
input=2*cos(2*pi*1005*t);
carrier=5*cos(2*pi*(1e4)*t+0.1*randn);
output=(2+0.5*input).*carrier;
nosie=randn(size(t));
r=nosie+output;
subplot(3,1,1);plot([0:dt:T],input);
subplot(3,1,2);plot([0:dt:T],carrier);
subplot(3,1,3);plot([0:dt:T],r);
set(gcf,'DoubleBuffer','on');
drawnow;
end