preprocessing.py 文件源码

def low_pass_filter(self, sig, low_cut, high_cut, nyq):

        """ 
        Apply a low pass filter to the data to take the relevant frequencies
        and to smooth the drop-out regions

        No resample necessary because all files have the same sampling frequency
        """

        b, a = signal.butter(5, np.array([low_cut, high_cut]) / nyq, btype='band')
        sig_filt = signal.lfilter(b, a, sig, axis=0)

        return(np.float32(sig_filt))