fg_06_14.m

英文书《Digital Signal Processing with Examples in MATLAB》附带的MATLAB实例

% fg_06_14  Phases of 6.12 and 6.13.
sp_fig(1);
band=[1 3];
r=[1 300]; s=[300 400];
t=str2mat('Lowpass','Bandpass');
for i=1:2
   [d,c]=bw_analog_weights(band(i),6,tan(pi*0.3),tan(pi*0.4));
   [b,a]=bilin(d,c);
   [H,v]=gain(b,a,500);
   ph=180*unwrap(angle(H))/pi;
   subplot(2,1,i);
   axis([0 .5 min(ph) max(ph)]); grid on;
   set(gca,'fontname','times','fontsize',16);
   line(v,ph,'color','k');
   line(v(r(i):s(i)),ph(r(i):s(i)),'color','k','linewidth',2);
   ylabel('Phase (deg.)');
   title(t(i,:));
end
xlabel('Hz-s');