[51qiang168]

f1=35;f2=50;dt=0.004;
n=0:149;
x=sin(2*pi*f1*n*dt);
y=0.8*cos(0.4*pi*n)*exp(-100*n.^2*dt.^2);
figure(1);
stem(x,'.');
figure(2);
stem(y,'.');
matlab中总是报错：??? Error using ==> mtimes
Inner matrix dimensions must agree.

Error in ==> Untitled2 at 5
y=0.8*cos(0.4*pi*n)*exp(-100*n.^2*dt.^2);
把y=..............这个去掉或者是把y=..........后面的exp(...)去掉就正常，为什么？？？？？？？？？？？