I have an IIR filter I am trying to plot, but I am not sure what I am doing wrong here. Can someone please help?
%% This is a first part of an exercise.
% Here you are implementing the transfer function H(z).
% Pass different values of theta and r to have differnt outcome.
clc; clear all;
%% Part -1 simulation
% initialize r
r = 0.99 ;
theta = pi/3 ;
% initialize omega vector. Let, ω to start from 0 to pi with % 200 intermediate values.
w = 200 ;
% Now, define z = e^(j*w).
z = exp(1i*w);
% implement H
H = 1./(1 - (2*r*cos(theta)*(z.^-1))+((r^2)*(z.^-2)));
% Now, plot the filter magnitude response in dB scale w.r.t w.
figure;plot(w, );grid on;
xlabel('normalized frequency'); ylabel('amplitude in dB')
title('Frequency and phase response at r = and theta = ');