拉格朗日插值多项式用matlab实现，目前网上的都是用多层for循环 这没有利用到矩阵的强大功能，matlab就是以矩阵为基础建立的科学软件。对矩阵的运算非常适合。提高运算效率。(The Lagrange interpolation polynomial is realized by MATLAB, and at present, the network is all multilayered for cycle This does not take advantage of the pow