I get Vectors must be the same length. error

Hello, maybe someone know why I get this error?

F=1000;
Fn=F/2;
f=[0:20:160 180 200 220 240:20:500] ;

am=[ones(1,9) 0.9 0.5 0.1 zeros(1,14)];
fn=f/Fn;
N=32;
a=1;
b=firls(N, fn, am);
H=freqz(b, a, 1000);

w=hamming(N); 

figure(2);
plot(w*Fn/pi, abs(H));

Thanks in advance

[Jan]

I've edited the code today. Please use the "{} Code" button the next time. Thanks.

[Manashee Malita]

For the function "plot(x,y)", if x and y are some vector or matrix, they must have same length or size. If you assume x=w*Fn/pi and y=abs(H), then you can observe that the size of x and y are different. Regards M.Kalita

Answer 1

[Star Strider]

Request 2 outputs from your freqz call, rather than creating your own frequency vector:

[H,w]=freqz(b, a, 1000);

figure(2);
plot(w, abs(H));