signal.py 文件源码

def bandpass(w, freqlo, freqhi, fs, npass=2):
    wn = [2*freqlo/fs, 2*freqhi/fs]
    (b,a) = signal.butter(npass, wn, btype='band')
    w = signal.lfilter(b, a, w)
    return w


# A forward-backward linear filter (filtfilt) (added by DmBorisov)