fg_06_10.m

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

% fg_06_10  Chebyshev translation.
L=10;
wc=.32;
w1=.32;
w2=.64;
dB=-100;
sp_fig(1);
clr=['r' 'g' 'b' 'c'];
ax=[1 .3 .6 .2];
ay=[2.5 .4 2.5 .8];
axvect=[-1 .1 -2.5 2.5; -2.5 .1 -1 1; -2.5 .1 -1 1; -2.5 .1 -1 1];
ttl=str2mat('Lowpass','Highpass','Bandpass','Bandstop');
for band=1:4,
    [d,c]=ch_analog_weights(band,L,dB,w1,w2);
    z=-d(:,2)./d(:,1);                          % zeros
    p=-c(:,2)./c(:,1);                              % poles
    subplot(2,2,band);
    axis([-ax(band) .1 -ay(band) ay(band)]);
   set(gca,'fontsize',14); grid;
   x=real(p'); y=imag(p');
   line([x x],[y -y],'linestyle','none','marker','x','color',clr(band));
   x=real(z); y=imag(z);
   line([x x],[y -y],'linestyle','none','marker','o','color',clr(band));
   if(band>2)
      xlabel('Re(s)');
   end
   line([0 0],[-3 3],'color','k');
   line([-1 1],[0 0],'color','k');
   ylabel('Im(s)');
   title(ttl(band,:));
end