iir_2type.m

很多matlab的源代码

figure('position',[10 10 800 500], 'name','模拟原型低通滤波器');
wq1=uicontrol('style','popupmenu',...
    'position',[50 440 250 20],...
    'string','Butterworth 低通滤波器|Chebyshev-I低通滤波器');

subplot(1,1,1);
Wp = 0.2*pi;
Ws = 0.3*pi;
Rp = 7;
As = 16;
[b,a] = afd_butt(Wp,Ws,Rp,As);
[C,B,A] = sdir2cas(b,a)
[db,mag,pha,w] = freqs_m(b,a,0.5*pi);
subplot(3,2,3);
plot(w/pi,mag);grid
axis([0 0.5 0 1.2]);
subplot(3,2,4);
plot(w/pi,db);grid
axis([0 0.5 min(db) max(db)+2])
subplot(3,2,5);
plot(w/pi,pha);grid
axis([0 0.5 min(pha) max(pha)])
[ha,x,t] = impulse(b,a);
subplot(3,2,6);
plot(t,ha);grid
axis([0 30 min(ha) max(ha)])


set(wq1,'Callback','IIR_2type_sub');