说明：  自己编写的ChebyshevI型滤波器的源程序.对于毕业设计的同学,很有参考价值.它是ChebyshevI型低通滤波器
(their ChebyshevI prepared by the filter type of the source. Design for graduate students, great reference value. It is ChebyshevI-type low-pass filter)