说明：  这个程序用来说明单频离散序列的周期延拓和补零延拓会对频域的分辨率有什么影响，是我自己刚作出来的，就贡献了吧，请您审查通过
(the procedure used to describe single-frequency cycle sequence of discrete Extension and Extension-zero frequency domain will have a resolution of any impact option is my own just to make the contribution on the right, please review by Thank you)