TimeSignals.py 文件源码

def bandPass(df , fmin = None, fmax = None , unit = "Hz" ) :
   """
      Return filtered signal
   """
   from scipy.fftpack import rfft, irfft, rfftfreq  #Warning convention of scipy.fftpack != numpy.fft   !!!
   if type(df) == pd.Series :
      df = pd.DataFrame(df)
      ise = True
   else :
      ise = False
   filtered = pd.DataFrame( index = df.index  )
   W = rfftfreq( df.index.size, d = dx( df ) )
   for col in df.columns :
      tmp = rfft(df[col])
      if fmin is not None :
         tmp[ ( W < fmin) ] = 0
      if fmax is not None :
         tmp[ ( W > fmax) ] = 0
      filtered[col] = irfft(tmp)
   if ise :
      return filtered.iloc[:,0]
   else :
      return filtered