get_poly_lagrange

function poly_lagrange = get_poly_lagrange(nodes,f_labels,x)
  number = 1;
  for k = 1:length(x)
    res = 0;
    for i = 1:length(nodes)
      l_i = 1;
        for j = 1:length(nodes)
            if ~(i == j)
                l_i = l_i * ((x(k) - nodes(j)))/(nodes(i) - nodes(j));
            end
        end
        res = res + f_labels(i) * l_i;
    end
    poly_lagrange(number) = res;
    number = number + 1;
  end 
end