中文说明：自己编写的多项式拟合程序，阶数可选择，里面含有一个数据文件，下载即可运行，使用过程中也可以用自己的数据。
English Description：
The polynomial fitting program written by myself has optional order. It contains a data file, which can be downloaded and run. You can also use your own data in the process of use.