code: def lifter(cepstra, L=22):
      """Apply a cepstral lifter the the matrix of cepstra. This has the effect of increasing the
      magnitude of the high frequency DCT coeffs.
  
      :param cepstra: the matrix of mel-cepstra, will be numframes * numcep in size.
      :param L: the liftering coefficient to use. Default is 22. L <= 0 disables lifter.
      """
      if L > 0:
          nframes, ncoeff = numpy.shape(cepstra)
          n = numpy.arange(ncoeff)
          lift = 1 + (L / 2.0) * numpy.sin(numpy.pi * n / L)
          return lift * cepstra
      else:
          # values of L <= 0, do nothing
          return cepstra
  
file_path: python_speech_features/python_speech_features/base.py
imports: from __future__ import division
  import numpy
  from python_speech_features import sigproc
  from scipy.fftpack import dct
label_desc: Use image node_id 9 for calling a global function with example usage: lifter(cepstra, L) and returns: unknown, cepstra