fg_06_11.m

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

% fg_06_11  Analog & digital gain.
N=500; L=2; w1=2;
w=linspace(0,w1,N);
sp_fig(1,8,4);

% Analog
subplot(1,2,1);
axis([0 w1 0 1]);
set(gca,'fontsize',16);
P=1./(1+w.^(2*L));
line(w,P,'color','r'); grid;
line([1 1],[0 .5],'color','k','linestyle',':')
set(gca,'xtick',0,'ytick',[0 .5 1]);
set(gca,'position',[0.13 0.16 0.33 0.92-.18]);
h=text(.65,-.06,'tan(\pi\nu_c)');
   set(h,'fontsize',16);
xlabel('Frequency \omega (rad/s)');
ylabel('Power gain, |H_A(j\omega)|^2');
title('Analog');

% Digital
v=linspace(0,.5,500);
subplot(1,2,2);
axis([0 .5 0 1]);
set(gca,'fontsize',16);
P=1./(1+tan(pi*v).^(2*L));
line(v,P,'color','b'); grid;
line([1 1]*.5/2,[0 .5],'color','k','linestyle',':')
set(gca,'xtick',0,'ytick',[0 .5 1]);
set(gca,'position',[0.58 0.16 0.33 0.92-.18]);
h(1)=text(.45*.5,-.04,'\nu_c');
h(2)=text(.95*.5,-.035,'0.5');
set(h,'fontname','times','fontsize',16);
xlabel('Frequency \nu (Hz-s)');
ylabel('Power gain, |H(e^{j2\pi\nu})|^2');
title('Digital');