埃特金等距插值。geidingn个等距节点的函数值及精度要求，用埃特金逐步插值法计算指定插值点t处的函数近似值-Interpolation with Aitken equidistance method. Using Aitken interpolation method to get the near value of target point, and this method can satisfy the precision and values of geidingn points