Rp=1;
Rs=60;
Wp=.30;
Ws=.35;
%
[N,Wn]=buttord(Wp,Ws,Rp,Rs);[b,a]=butter(N,Wn);        %Butterworth
%[N,Wn]=cheb1ord(Wp,Ws,Rp,Rs);[b,a]=cheby1(N,Rp,Wn);    %Csebisev
%[N,Wn]=cheb2ord(Wp,Ws,Rp,Rs);[b,a]=cheby2(N,Rs,Wn);    %Inverz Csebisev
%[N,Wn]=ellipord(Wp,Ws,Rp,Rs);[b,a]=ellip(N,Rp,Rs,Wn);   %Elliptikus
[N,Wn]
[H,w]=freqz(b,a);
figure(1)
%plot(w/pi,abs(H))
plot(w/pi,20*log10(abs(H)+eps))
grid on
figure(2)
plot(w/pi,unwrap(angle(H)))
x=ones(1000,1);
%x=zeros(1000,1);x(1)=1;
y=filter(b,a,x);
%
figure(3);plot(y)

