functions.py 文件源码

def besselFilter(data, cutoff, order=1, dt=None, btype='low', bidir=True):
    """return data passed through bessel filter"""
    try:
        import scipy.signal
    except ImportError:
        raise Exception("besselFilter() requires the package scipy.signal.")

    if dt is None:
        try:
            tvals = data.xvals('Time')
            dt = (tvals[-1]-tvals[0]) / (len(tvals)-1)
        except:
            dt = 1.0

    b,a = scipy.signal.bessel(order, cutoff * dt, btype=btype) 

    return applyFilter(data, b, a, bidir=bidir)
    #base = data.mean()
    #d1 = scipy.signal.lfilter(b, a, data.view(ndarray)-base) + base
    #if (hasattr(data, 'implements') and data.implements('MetaArray')):
        #return MetaArray(d1, info=data.infoCopy())
    #return d1