信息论与编码实验程序与结果图(matlab)(共5页).doc

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1、精选优质文档-倾情为你奉上结果图信源熵实验程序：clc; close all; clear;linwidd=1fontt=20p0=0; pd=1; N=20p=linspace(p0,pd,N);I=-log2(p);plot(p,I,k);title(I=-log2(p)函数图);xlabel(p);ylabel(I); clc; close all; clear;linwidd=1fontt=20p0=0; pd=1; N=20p=linspace(p0,pd,N);H=-p.*log2(p)-(1-p).*log2(1-p);plot(p,H,k);title(H=-p.*log2(p

2、)-(1-p).*log2(1-p)函数图);xlabel(p);ylabel(H);信道容量实验程序：clc; close all; clear;linwidd=1fontt=20p0=0; pd=1; N=20p=linspace(p0,pd,N);r=4c=log2(r)+(1-p).*log2(1-p)+p.*log2(p/(r-1);plot(p,c,k);title(强对称信道容量数值模拟图);有噪信道编码-费诺不等式程序： 结果图clc;close all;clear;r=3;p0=0.00001;pd=0.99999;N=2000;p=linspace(p0,pd,N);q=1

3、-p;H=-p.*log2(p)-q.*log2(q);hold onHH=H+p.*log2(r-1)title(费诺不等式示意图);box onxlabel(PE);ylabel(H(X/Y);plot(p,HH,k:)hold onhold onfill(p,1,HH,0,0.6,0.6,0.6)stem(r-1)/r,1.59,-.r)text(0.66,1.6,最大值)专心-专注-专业香农编码程序：clc;clear all;close all;p=0.2 0.19 0.18 0.17 0.15 0.1 0.01;if sum(p)1 error(输入概率不符合概率分布)endp i

4、ndex=sort(p,descend);n=length(p);pa=zeros(n,1);for ii=2:n pa(ii)=pa(ii-1)+p(ii-1);endk=ceil(-log2(p);%码字长度计算c=cell(1,n);%生成元胞数组，用来存不同长度的码字for ii=1:n cii=; tmp=pa(ii); for jj=1:k(ii) tmp=tmp*2; if tmp=1 tmp=tmp-1; %ciijj=1; cii=char(cii),1; else %ciijj=0; cii=char(cii),0; end endendc(index)=c;%换回原来的顺

5、序codelength=zeros(1,n);%码长初始化for ii=1:n fprintf(第,num2str(ii),个消息对应为); disp(cii);%显示码字 codelength(ii)=length(cii);%endn_average=sum(codelength.*p) %平均码长fprintf(平均码长为);disp(n_average);H=-sum(p.*log2(p);fprintf(信源熵);disp(H);x=H/(n_average.*log2(2)fprintf(编码效率);disp(x);figureh=stem(1:n,codelength);%axi

6、s(0 n+1 0 n+1);set(h,MarkerFaceColor,blue,linewidth,2)实验结果 结果图第1个消息对应为000第2个消息对应为001第3个消息对应为011第4个消息对应为100第5个消息对应为101第6个消息对应为1110第7个消息对应为n_average = 3.1400平均码长为 3.1400信源熵 2.6087x =0.8308编码效率 0.8308费诺编码程序： end for rr=2:2:needgroupnum*2 index2=index_aftergroup(rr,:); for ii=index2(1):index2(2) cii=cha

7、r(cii),1; end end flag=0; index_p=; for rr=1:needgroupnum*2indextmp=index_aftergroup(rr,:); if(indextmp(2)-indextmp(1)+11) flag=1; index_p=index_p;indextmp; end end jj=jj+1;endc(index)=c;codelength=zeros(1,N);for ii=1:N fprintf(第,num2str(ii),个消息对应为); disp(cii); codelength(ii)=length(cii);endn_averag

8、e=sum(codelength.*p)fprintf(平均码长为);disp(n_average);H=-sum(p.*log2(p);fprintf(信源熵);disp(H);x=H/(n_average.*log2(2)fprintf(编码效率);disp(x);figureh=stem(1:N,codelength);axis(0 N+1 0 N+1);set(h,MarkerFaceColor,blue,linewidth,2)endfunction index_aftergroup=func_group(p,index_p)index=index_p(1):index_p(2);n

9、=length(index);p0=p(index);sump0=sum(p0);half_sump0=sump0/2;for ii=1:n-1 tmpsum=sum(p0(1:ii); if abs(tmpsum-half_sump0)1&B(i,j)=B(i-1,j) d=d+1; else d=1; end B(B(n,j+1),j+1)=-1; temp=B(:,j+1); x=find(temp=B(i,j); ENDc(i)=ENDc1(x(d); endy=B(n,j+1);ENDc(t-1)=char(ENDc1(y),1;ENDc(t)=char(ENDc1(y),0;t=t

10、+1;ENDc1=ENDc;endA%排序后的原概率序列ENDc%编码结果for i=1:n a,b=size(char(ENDc(i); L(i)=b;endavlen=sum(L.*A)%平均码长selen=(L-avlen).2%?mselen=sum(selen).*A)%码长均方差H=-A*(log2(A)%?P=H/avlen%?figure;subplot(2,1,1)h=stem(1:n,selen);%axis(0 n+1 0 max(selen)+0.1);set(h,MarkerFaceColor,blue,linewidth,2)xlabel(信源向上排);ylabel

11、(方差值selen);hold onplot(0:n+1,mselen*ones(1,n+2),r,linewidth,2);hold offlegend(每个信源码长与平均码长的方差,码长均方差);A=0.4 0.2 0.2 0.1 0.1;A=sort(A,descend);T=A;m,n=size(A);B=zeros(n,n-1);B(:,1)=T;r=B(n,1)+B(n-1,1);T(n-1)=r;T(n)=0;T=sort(T,descend);t=n-1;for j=2:n-1 B(1:t,j)=T(1:t); K=find(T=r); B(n,j)=K(end); %B(n,

12、j)=K(1); r=(B(t-1,j)+B(t,j); T(t-1)=r; T(t)=0; T=sort(T,descend); t=t-1;endB;ENDc1=sym(1,0);ENDc=ENDc1;t=3;d=1;for j=n-2:-1:1 for i=1:t-2 if i1&B(i,j)=B(i-1,j) d=d+1; else d=1; end B(B(n,j+1),j+1)=-1; temp=B(:,j+1); x=find(temp=B(i,j); ENDc(i)=ENDc1(x(d); endy=B(n,j+1);ENDc(t-1)=char(ENDc1(y),1;ENDc

13、(t)=char(ENDc1(y),0;t=t+1;ENDc1=ENDc;endA%排序后的原概率序列ENDc%编码结果for i=1:n a,b=size(char(ENDc(i); L(i)=b;endavlen=sum(L.*A)%平均码长selen=(L-avlen).2%?mselen=sum(selen).*A)%码长均方差H=-A*(log2(A)%?P=H/avlen%?subplot(2,1,2)h=stem(1:n,selen);%axis(0 n+1 0 max(selen)+0.1);set(h,MarkerFaceColor,blue,linewidth,2)xlab

14、el(信源向下排);ylabel(方差值selen);hold onplot(0:n+1,mselen*ones(1,n+2),r,linewidth,2);hold offlegend(每个码长与平均码长的方差,码长均方差);实验结果 A = 0.4000 0.2000 0.2000 0.1000 0.1000ENDc = 11, 1, 0, 101, 100avlen = 1.8000selen = 0.0400 0.6400 0.6400 1.4400 1.4400mselen =0.5600H =2.1219P =1.1788A =0.4000 0.2000 0.2000 0.1000 0.1000ENDc = 0, 10, 111, 1101, 1100avlen =2.2000selen = 1.4400 0.0400 0.6400 3.2400 3.2400mselen =1.3600H =2.1219P =0.9645结果图