用于时频分析算法，预报误差法参数辨识-松弛的思想，FIR 底通和带通滤波器和IIR 底通和带通滤波器。- For time-frequency analysis algorithm, Prediction Error Method for Parameter Identification- the idea of relaxation, Bottom-pass and band-pass FIR and IIR filter bottom pass and band-pass filter.