function matrix=circ(v0)
%v0=[1 2 3 4 5 6 7 8 9]';
[r,c] = size(v0);
N=r;

matrix = zeros(N,N);
offset = 0;
for j=1:N
   for i=0:N-1
      matrix(i+1,j)= v0(mod(i+offset,N)+1);
   end
   offset = offset + N-1;
end