Filter.py 文件源码

def apply_bandpass_filter(data, f_low, f_high, filter_bw=0.08):
        if f_low > f_high:
            f_low, f_high = f_high, f_low

        f_low = util.clip(f_low, -0.5, 0.5)
        f_high = util.clip(f_high, -0.5, 0.5)

        h = Filter.design_windowed_sinc_bandpass(f_low, f_high, filter_bw)

        # Choose normal or FFT convolution based on heuristic described in
        # https://softwareengineering.stackexchange.com/questions/171757/computational-complexity-of-correlation-in-time-vs-multiplication-in-frequency-s/
        if len(h) < 8 * math.log(math.sqrt(len(data))):
            logger.debug("Use normal convolve")
            return np.convolve(data, h, 'same')
        else:
            logger.debug("Use FFT convolve")
            return Filter.fft_convolve_1d(data, h)