说明：  该程序可用matlab实现三种滤波：切比雪夫1,切比雪夫2和巴特沃斯滤波。可实现信号的滤波预处理。
(The program can be used to achieve three filtering matlab: Chebyshev 1, Chebyshev 2 and Butterworth filter. The filter can be realized signal preconditioning.)