Huffman.m
上传用户:loeagle
上传日期:2013-03-02
资源大小:1236k
文件大小:1k
- function [h,l]=huffman(p);
- %HUFFMAN Huffman code generator
- % [h,l]=huffman(p), Huffman code generator
- % returns h the Huffman code matrix, and l the
- % average codeword length for a source with
- % probability vector p.
- if length(find(p<0))~=0,
- error('Not a prob. vector, negative component(s)')
- end
- if abs(sum(p)-1)>10e-10,
- error('Not a prob. vector, components do not add up to 1')
- end
- n=length(p);
- q=p;
- m=zeros(n-1,n);
- for i=1:n-1
- [q,l]=sort(q);
- m(i,:)=[l(1:n-i+1),zeros(1,i-1)];
- q=[q(1)+q(2),q(3:n),1];
- end
- for i=1:n-1
- c(i,:)=blanks(n*n);
- end
- c(n-1,n)='0';
- c(n-1,2*n)='1';
- for i=2:n-1
- c(n-i,1:n-1)=c(n-i+1,n*(find(m(n-i+1,:)==1))...
- -(n-2):n*(find(m(n-i+1,:)==1)));
- c(n-i,n)='0';
- c(n-i,n+1:2*n-1)=c(n-i,1:n-1);
- c(n-i,2*n)='1';
- for j=1:i-1
- c(n-i,(j+1)*n+1:(j+2)*n)=c(n-i+1,...
- n*(find(m(n-i+1,:)==j+1)-1)+1:n*find(m(n-i+1,:)==j+1));
- end
- end
- for i=1:n
- h(i,1:n)=c(1,n*(find(m(1,:)==i)-1)+1:find(m(1,:)==i)*n);
- l1(i)=length(find(abs(h(i,:))~=32));
- end
- l=sum(p.*l1);