function [U,DV] = DiffDiv(Lx,Ly)
N = size(Lx,2)-1; U = zeros(N+1,N+2); 
U(:,1) = conj(Lx'); U(:,2) = conj(Ly'); 
DV = [Ly(1)]; 
for j=2:N+1
    for i=1:N+2-j 
        U(i,j+1)= (U(i,j)-U(i+1,j))/(U(i,1) - U(i+j-1,1)); 
    end    
    DV = [U(1,j+1) DV];
end 
U = U(:,2:N+2)   
endfunction
