close all
clear all
echo off
i=1:500;
a=randn(1,500);%

[sqnr,a_quan,code]=u_pcm(a,8);%調用均勻量化函數
f=a-a_quan;                 %量化誤差等于原始值與量化值的差
subplot(3,1,1);
axis([0 500 -1 1]);
plot(i,f,'-');
title('量化誤差,從上到下量化級數分別為8,16,64')

[sqnr,a_quan,code]=u_pcm(a,16);
f=a-a_quan;                 
subplot(3,1,2);
axis([0 500 -1 1]);
plot(i,f,'-');


[sqnr,a_quan,code]=u_pcm(a,64);
f=a-a_quan;                 
subplot(3,1,3);
axis([0 500 -1 1]);
plot(i,f,'-');