huffman.m

利用MATLAB实现哈弗曼编码。 利用MATLAB实现哈弗曼编码。

function [h,l]=huffman(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);