gs_weighted.m

在matlab中

function clist = gs_weighted(M,L,k)

% clist = gs_weighted(M,L,k)
%
% Decode a Reed-Solomon code using a multiplicity matrix and
% Guruswami-Sudan algorithm.  The algorithm is described in the
% paper "Improved Decoding of Reed-Solomon Codes and
% Algebraic-Geometry Codes," IEEE Transactions on Information
% Theory, September 1999.  
%
% The inputs are the multiplicity matrix M, the tolerable y-degree
% in the interpolation L, and the polynomial degree k.

q = size(M,1);
m = log2(q);
n = q - 1;
a = gf(2,m);
alphas = a.^(0:(n-1));

% interpolate a polynomial
Q = koetter_interp(L, alphas, M, k);

% find the roots
clist = rr_factor(Q,k+1,m);

% make the list pretty
clist = clist(2:end,:);
clist = [clist zeros(size(clist,1),k-size(clist,2))];
clist = fliplr(clist);