huffman.m

霍夫曼编码程序 对给定的概率 生成霍夫曼编码 希望大家给点意见

function [h,l]=huffman(p)
if length(find(p<0))~=0,%判断输入是否概率分布
    error('Input is not a prob vector,there is negative component')
end
if ans(sum(p)-1)>10e-10
    error('input is not a prob.vector,the sum of the components is not equal to 1')
end
n=length(p);%得到输入的元素个数
q=p;
m=zeros(n-1,n);
for i=1:n-1
    [q,l]=sort(q);%将输入的概率元素排序
    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,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,l:n)=c(1,n*(find(m(1,:)==i)-1)+1:find(m(1,:)==i)*n);
    l(i)=length(find(abs(h(i,:))~=32));
end
l=sum(p.*l)