butterbandstop.m

IIR滤波器的matlab实现

clc
clear
close all

%IIR
%bandpass
fs=1000;%Sample frequence
fpass=[50 250];
fstop=[100 200];
Wp = fpass/(0.5*fs); Ws = fstop/(0.5*fs);
Rp = 3; Rs = 40;
[n,Wn] = buttord(Wp,Ws,Rp,Rs)
[b,a]= butter(n,Wn,'stop');
freqz(b,a,128,fs); title('butter bandstop');