filter

代码说明：

  巴特沃斯和切比雪夫滤波器,其中前者为低通,后者为带通,可有效滤除不同频噪声.(Butterworth and Chebyshev filter, where the former is a low-pass, band-pass which can effectively filter out different frequency noise.)

文件列表：

butlow.m,276,2013-08-30
chebband.m,320,2013-08-30