% Odpowiedź impulsowa
imp = zeros(10,1);
imp(1) = 1;
B = [0 0.3];
A = [1 -0.7];
h = filter(B, A, imp);
stem((0:9),h);
% Dane
N = 1024;
k = [0:N-1];
Om = 2*pi/N;
e = exp(-j*Om*k);
H = (0.3*e)./(1 - 0.7*e);
% Ch-ka amp-faz
figure;
plot(H(1:N/2+1)); % amp-faz
figure;
plot([0:(N/2)]*Om, abs(H(1:N/2+1))); % amp
figure;
plot([0:(N/2)]*Om, angle(H(1:N/2+1))); % faz
B = [0 0.3];
A = [1 -0.7];
 u = randn(1000, 1);
 y = filter(B, A, u);
 fp = 1000;
 % GWM u
 figure;
 X = fft(u,fp);
 GWM = ((abs(X)).^2)/fp;
 plot(0:fp/2,10*log10(GWM(1:(fp/2)+1)))
 % GWM y
 hold on;
 X = fft(y,fp);
 GWM = ((abs(X)).^2)/fp;
 plot(0:fp/2,10*log10(GWM(1:(fp/2)+1)))