%輸入數字濾波器的指標
clear?all;
wp=0.2*pi;
ws=0.5*pi;
Rp=3;
As=15;
fs=1/2;
%按照預畸公式換算為模擬指標
Wp=2*fs*tan（wp/2）;Ws=2*fs*tan（ws/2）;
%根據指標確定butterworth濾波器的階數N和3dB截止頻率Omegac??
N=ceil（（log10（（10^