polysubm.m

压缩文件中是Error Correction Coding - Mathematical Methods and Algorithms(Wiley 2005)作者:(Todd K. Moon )的配

function p = polysub(a,b,m)
% subtract the polynomials p=a-b modulo m
% The polynomials are represented with the HIGHEST coefficient first
% e.g., x^2 + 3x + 4 -- [1 3 4],   x^2 + 3x --- [ 1 3 0]

% Copyright 2004 by Todd K. Moon
% Permission is granted to use this program/data
% for educational/research only

k = length(b) - length(a);
p = mod([zeros(1,k) a] - [zeros(1,-k) b],m);
if(all(p==0))
  p = 0;
else
  p = p(find((p==0)==0):end);   % get rid of leading zeros
end