function []=test(G)
[k,N]=size(G);
p = randsrc(1,k,[0 1 ; 0.5 0.5]);
Ht = G2HT(G);
f = mod(p*G,2);
e = randerr(1,N,1);
j = mod(f+e,2);
disp(j);
p = decode(j,Ht);

disp(p);

end

function [p] = decode(j,Ht)
if (HT2G(Ht)*Ht) ==1
    p = j;
end
[N,r]=size(Ht);
s = mod(j*Ht,2);
for i=1:N,
   if s == Ht(i,:)
        j(i) =~ j(i);
   end
end
p = j(1:N-r);



end

function [G] = HT2G(Ht)

[N,r]=size(Ht);
G = [eye(N-r),Ht(1:N-r,:)];

end

function [Ht] = G2HT(G)

[K,N]=size(G);
Ht = [G(:,K+1:N);eye(N-K)];

end


KODER

function [f]=koder(P,g)

k = length(P);
r = length(g)-1;

f = [P zeros(1,r)];

[M,R] = deconv(f,g);

R = mod(R,2);
f = f+R;

end