fg_07_05.m

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

% fg_07_05   Gaussian distributions.
sp_fig(1,9,4);
subplot(1,2,1);
axis([-4 5 0 .5]);
set(gca,'fontsize',16);
set(gca,'xtick',[-4:4],'xticklabel',[ ]);
set(gca,'position',[0.1300    0.1100    0.3270    0.78]);
h=0; h(1)=text(0-.1,-.03,'\mu');
h(2)=text(1-.5,-.03,'\mu+\sigma');
h(3)=text(-1-.5,-.03,'\mu-\sigma');
set(gca,'ytick',[0:.1:.5],'yticklabel',[]);
N=540; x=[-N/2:N/2-1]*9/N;
y=exp(-x.^2/2)/sqrt(2*pi);
line(x,y,'color','r');
xp=[-2:2;-2:2];
yp=[zeros(1,5);y(2.5*N/9:N/9:6.5*N/9)];
line(xp,yp,'color','k','linestyle',':');
line([-1 0 1],[0 0 0],'color','k','linestyle','none','marker','.');
h(4)=text(-5,0,'0');
h(5)=text(-5.9,.2,'0.2/\sigma');
h(6)=text(-5.9,.4,'0.4/\sigma');
title('Continuous');
h(7)=text(5.2,0,'x');  h(8)=text(-3.6,.5,'p(x)');

subplot(1,2,2);
axis([-4 5 0 .2]);
set(gca,'fontsize',16);
set(gca,'xtick',[-4:4],'xticklabel',[ ]);
set(gca,'ytick',[0:.05:.2],'yticklabel','0| |.1| |.2');
set(gca,'position',[0.5780    0.1100    0.3270    0.78]);
N=18; x=[-N/2:N/2-1]*9/N;
y=exp(-x.^2/2)/sqrt(2*pi); y=y/sum(y);
line([x;x],[zeros(1,N);y],'color','k');
line(x,y,'linestyle','none','marker','*','color','b');
title('Discrete');
h(9)=text(5.2,0,'n');  h(10)=text(-3.6,.2,'P_n');
set(h,'fontsize',16);