function [DD] = tablaDiferencias(x,y)
    x = x(:);
    y = y(:);
    n = size(x,1);
    m = size(y,1);
    DD = zeros(n,m+1);
    DD(:,1) = y;
    for j=1:m
        for i=1:n-j
            Djfi = ( DD(i+1,j) - DD(i,j) )/( x(i+j) - x(i) );
            DD(i,j+1) = Djfi;
        end
    end
endfunction