Timbral_Metallic.py 文件源码

def butter_lowpass(cutoff, fs, order=2):
    """
     This function calculates the butterworth filter coefficients for a given cutoff frequency and order.

     :param cutoff: Cutoff frequency as a proportion of the Nyquist frequency (Freq (Hz) / (Sample rate / 2))
     :param fs:     Sample rate of signal to be filtered
     :param order:  Filter order, defaults to second order filter, as required by timbral_metallic
     :return: returns the coefficients of a Butterworth filter
    """
    nyq = 0.5 * fs
    normal_cutoff = cutoff / nyq
    b, a = butter(order, normal_cutoff, btype='low', analog=False)
    return b, a