freqz() and plot()

[Sneha]

Hello,
I am struggling for a simple plot function.
I want to plot two plots....
One is freqz to display frequency responce of a filter and one is normal plot command to show variance in output due to fixed point constraints.

Now when I run the code, only one of the two plots stays, other one disappers quickly.
I tried using subplot with freqz but it doesnot work.
Can you please help me out with this?
How to make both the plots stay?
Thanks

[Wayne King]

"Sneha " <sd...@audience.com> wrote in message <ic3s3n$jvq$1...@fred.mathworks.com>...

Hi,
You can do something like this (just an example with some simple FIR filters)

b1 = 0.1*ones(10,1);
b2 = 0.05*ones(20,1);
[h1,w1] = freqz(b1,1,512);
[h2,w2] = freqz(b2,1,512);
plot(w1,20*log10(abs(h1)),'b');
hold on;
plot(w1,20*log10(abs(h2)),'r');
ylabel('dB'); xlabel('Radians/sample');

You can also use fvtool() to plot both your original filter and your quantized filter response:

fvtool(b1,1,b2,1);

Hope that helps,
Wayne

[Sneha]

"Wayne King" <wmki...@gmail.com> wrote in message <ic3v73$g3q$1...@fred.mathworks.com>...

Thank you Wayne.
I really appreciate.