fg_07_18.m

来自「英文书《Digital Signal Processing with Examp」· M 代码 · 共 21 行

% fg_07_18         PDS of filtered Gaussian noise - changing K.
sp_fig(1,9,5.5);
set(gcf,'defaultaxesfontsize',16);

N=2^10; NH=500; y2=2; K=[64,32,16];
randn('seed',12345);
x=randn(1,N);
[b,a]=ch_weights(3,8,-40,.1,.4);
H=abs(gain(b,a,NH)).^2;
y=filters(b,a,x);

for i=1:3,
    subplot(1,3,i);
    [p,Nsg]=pds(y,y,K(i),1,.95);
    bar2([0:K(i)/2]/K(i),p(1:K(i)/2+1),'r'); grid on;
    h=line([0:NH-1]*.5/NH,H,'color','b','linewidth',1.5);
    axis([0 .5 0 y2]);
    xlabel('\nu (Hz-s)'); ylabel('Power density, P_y(\nu)');
    title(['N=',int2str(K(i))]);            % Title modified for slide show.
end