Thread Subject: freqz to plot frequency response

I am trying to test plotting the frequency response of the simple system H(w) = 2 * e^(-jw). It's obvious that the magnitude of the frequency response in theory should be 2, and the phase should be (-w).

However, the code below doesn't get me the above plot. What's wrong with the code?

omega=(0:400)*pi/400; b=[1,2];
H=freqz(b,1,omega);
subplot(211); plot(omega/pi,abs(H))
subplot(212); plot(omega/pi,angle(H))

Regards,
Hao Zheng (Arthur)

b should b [0 2]?

-rajiv

"Arthur Zheng" <hzheng7@gatech.edu> wrote in message
news:gkm9nr$r1g$1@fred.mathworks.com...
>I am trying to test plotting the frequency response of the simple system
>H(w) = 2 * e^(-jw). It's obvious that the magnitude of the frequency
>response in theory should be 2, and the phase should be (-w).
>
> However, the code below doesn't get me the above plot. What's wrong with
> the code?
>
> omega=(0:400)*pi/400; b=[1,2];
> H=freqz(b,1,omega);
> subplot(211); plot(omega/pi,abs(H))
> subplot(212); plot(omega/pi,angle(H))
>
> Regards,
> Hao Zheng (Arthur)
>
>
>

oh, yes. thank you.

"Rajiv Singh" <rajiv_singh@msn.com> wrote in message <gkma9m$2gg$1@fred.mathworks.com>...
> b should b [0 2]?
>
> -rajiv
>
> "Arthur Zheng" <hzheng7@gatech.edu> wrote in message
> news:gkm9nr$r1g$1@fred.mathworks.com...
> >I am trying to test plotting the frequency response of the simple system
> >H(w) = 2 * e^(-jw). It's obvious that the magnitude of the frequency
> >response in theory should be 2, and the phase should be (-w).
> >
> > However, the code below doesn't get me the above plot. What's wrong with
> > the code?
> >
> > omega=(0:400)*pi/400; b=[1,2];
> > H=freqz(b,1,omega);
> > subplot(211); plot(omega/pi,abs(H))
> > subplot(212); plot(omega/pi,angle(H))
> >
> > Regards,
> > Hao Zheng (Arthur)
> >
> >
> >
>