>>ws=[0.40*pi 0.48*pi]; >> wp=[0.36*pi 0.52*pi]; >> Rp=0.5;As=50; >> [N,wn]=ellipord(wp/pi,ws/pi,Rp,As); >> [b,a]=ellip(N,Rp,As,wn,'stop'); >> [db,mag,pha,grd,w]=freqz_m(b,a); >> subplot(2,2,1);plot(w/pi,mag); >> subplot(2,2,2);plot(w/pi,db); >> n=[0:200]; >> x=sin(0.44*pi*n); >> y=filter(b,a,x); >> n1=length(y); >> subplot(2,2,3);plot(n,x); >> subplot(2,2,4);plot(0:(n1-1),y);