func_tools.py 文件源码

def band_pass(ite_data,freqmin,freqmax,samp_freq,corners=32):
    fe = samp_freq/2.0
    low = freqmin/fe
    high = freqmax/fe
    # raise error for illegal input
    if high - 1.0 > -1e-6:
        msg = ("Selected high corner frequency ({}) of bandpass is at or above Nyquist ({}). Applying a high-pass instead.").format(freqmax, fe)
        return False
    if low >1 :
        msg = "selected low corner requency is above Nyquist"
        return False

    z,p,k = signal.iirfilter(corners,[low,high],btype='band',ftype='butter',output='zpk')
    sos = zpk2sos(z,p,k)
    ite_data = sosfilt(sos,ite_data)
    ite_data = sosfilt(sos,ite_data[::-1])[::-1]
    return ite_data