function [L,U]=FactorisationLU(AA)

    n = size(AA,2);

// factorisation LU

    for j=1:n-1 do
        for i=j+1:n
            AA(i,j)=AA(i,j)/AA(j,j);
            for k=j+1:n do
                AA(i,k)=AA(i,k)-AA(i,j)*AA(j,k);
            end
        end
    end


    U=triu(AA,0);
    L=tril(AA,-1)+eye(3,3);

endfunction;

//============================================================

function [A]=InitA(n)

// Initialisation de la matrice de Vanermonde

    A= zeros(n,n);
    for i = 1:n do
        x(i)=i;
    end;
    for i = 1:n do
        for j = 1:n do
            A(i,j)=x(i)^(j-1);
        end
    end

endfunction

//============================================================

