基于等波动特性的切比雪夫(Chebyshev)函数的数字滤波设计（包括ChebyshevⅠ型和ChebyshevⅡ型的低通，高通，带通，带阻滤波器）-Based on the wave characteristics of Chebyshev design of digital filter function (low pass, including Chebyshev type I and type II Chebyshev high pass, band pass, band stop fi