#
1;

#================================
function Badd = add(x1,x2)
# description: this function takes two binary vectors x1,x2, and returns x1+x2
# mode 2.
# usgae: Badd = add(x1,x2)   
      n=rows(x1);
      x3=zeros(n,1);
      for i=1:n
            m=x1(i)+x2(i);
            if (m==1)  (x3(i)=1); endif;
            if (m==2)  (x3(i)=0); endif;
      endfor;
      Badd=x3;
endfunction
#=====================================
function Code=CodeGen(M)
# description: This function takes a generator of a certain code and returns
# the code itself. Each row of the matrix M is one generator.
# usage: Code=CodeGen(M)
[m,n]=size(M);
Prod=1;
for k=1:m
      Prod=Prod*2;
endfor;
C=zeros(Prod,n);
for i=1:m
      C(i,:)=M(i,:);
endfor;
posit=m;
for i=1:m
      for j=i+1:m
            #s=zeros(n,1)
            x=C(i,:)'
            s=x
            for k=j:m
                  posit=posit+1;         
                  y=C(k,:)'
                  #qq=add(x,y)
                  s=add(s,y) 
                  C(posit,:)=s'
            endfor;
      endfor;
endfor;
Code=C;
endfunction

#=====================================
function TwoFact=TF(n)
Prod=1;
for i=1:n
      Prod=Prod*2;
endfor;
TF=Prod;
endfunction
#=====================================
function BtoD=BtD(x)
[n,m]=size(x);
N=max(n,m);
s=x(1);
for i=2:N
      s=s+x(i)*TF(i-1);
endfor;
BtD=s;
endfunction

#=====================================
function Code=CodeGen(M)
# description: This function takes a generator of a certain code and returns
# the code itself. Each row of the matrix M is one generator.
# usage: Code=CodeGen(M)
[m,n]=size(M);
Prod=1;
for k=1:m
      Prod=Prod*2;
endfor;
C=zeros(Prod,n);
check=zeros(Prod,1);
for i=1:m
      C(i,:)=M(i,:);
      check(i)=BtD(C(i,:)');
endfor;
posit=m;
for i=1:m
      for j=1:m
            for k=1:m
Code=C;
endfunction

#=====================================

function [MVadd,flag1] = ad(M,v,check)
# description: This function takes a binary vectors v,a binary matrix M, and
# returns M+v mod 2.
# usgae: [MVadd,flag1] = ad(M,v,check) 
      [nn,n]=size(M);flag1=0;M1=M;
      x=zeros(n,1);y=zeros(n,1);
      for i=1:nn
            for j=1:n
                  x(j)=M1(i,j);
            endfor;
            #x=M1(i,:)';
            y=add(x,v);
            for k=1:8
                  if (check(k,:)==y')
                        (flag1=1);
                  endif;
            endfor;
            for j=1:n
                  M1(i,j)=y(j);
            endfor;

      endfor;
      MVadd=M1;
endfunction
#================


function [code,cosets] = findC(G)
# usage: [code,cosets]=findC(G)
# description: This function returns all the cosets of a certain code; where
# G is a generating matrix for the code.
[m,n]=size(G);
dif=n-m;
code=CodeGen(G)
C=code;
Prod=1;
for k=1:dif
      Prod=Prod*2;
endfor;
# NOTE: Prod gives the number of cosets.
[mm,nn]=size(C);
NN=mm*n;
r=zeros(Prod,NN);
# The matrix r will include all the cosets of the code. Every row will contain
# one coset. The elements of the coset are placed one after another in each
# row.
check=zeros(Prod,n);
# This matrix "check" contains one element of each different coset.
check(1,:)=C(1,:);
temp=[];
for tt=1:mm
      temp=[temp,C(tt,:)];
endfor;
r(1,:)=temp;
count=1;
for i=1:n
      ei=zeros(n,1);
      ei(i)=1;
      #flag=0;
      M=C;
      [M,flag]=ad(M,ei,check);

      if (flag==0)
            count=count+1;
            temp=[];
            for tt=1:mm
                  temp=[temp,M(tt,:)];
            endfor;
            r(count,:)=temp;       
            check(count,:)=M(1,:);
      endif;     
endfor;    
#count
check
if (count < Prod)
      for i=1:n
            for j=1:n
                  z=zeros(n,1);
                  id=eye(n,n);
                  ei=eye(i,:);
                  ej=eye(j,:);
                  s=zeros(n,1);
                  s=add(ei,ej);
                  if (s <> z)
                        M=C;
                        [M,flag]=ad(M,s,check);

                        if (flag==0)
                              count=count+1;
                              temp=[];
                              for tt=1:mm
                                    temp=[temp,M(tt,:)];
                              endfor;
                              r(count,:)=temp; 
           
                              check(count,:)=M(1,:);
                        endif;
                  endif;
            endfor;
      endfor;
endif;
#count
printf("Cosets:");printf(" ");     
# The purpose of the following for loop is to seperate the cosets and write
# them in the standard form, instead of being placed in one row.
for ii=1:Prod
      x=zeros(1,NN);
      x=r(ii,:);
      Ci=zeros(mm,n);
      #for ww=1:n
      #      Ci(1,ww)=x(ww);
      #endfor;
      for jj=1:mm
            d=(jj-1)*n;
            for kk=1:n
                  Ci(jj,kk)=x(d+kk);
            endfor;
      endfor;
      #printf("C(",ii,")");
      Ci
endfor;
                                               
cosets=r;  
endfunction