说明：  FIR 底通和带通滤波器和IIR 底通和带通滤波器，有详细的注释，包括邓氏关联度、绝对关联度、斜率关联度、改进绝对关联度。
( Bottom-pass and band-pass FIR and IIR filter bottom pass and band-pass filter, There are detailed notes, Including Deng s correlation, absolute correlation, correlation of slope, improved absolute correlation.)