code: def plot_frequencies(self, mindB=None, maxdB=None, norm=True):
          
          from pylab import plot, title, xlim, grid, ylim, xlabel, ylabel
          # recompute the response
          self.compute_response(norm=norm)
  
          plot(self.frequencies, self.response)
          title("ENBW=%2.1f" % (self.enbw))
          ylabel('Frequency response (dB)')
          xlabel('Fraction of sampling frequency')
          # define the plot limits
          xlim(-0.5, 0.5)
          y0, y1 = ylim()
          if mindB:
              y0 = mindB
          if maxdB is not None:
              y1 = maxdB
          else:
              y1 = max(self.response)
  
          ylim(y0, y1)
  
          grid(True)
docs: Plot the window in the frequency domain
  
          :param mindB: change the default lower y bound
          :param maxdB: change the default upper lower bound
          :param bool norm: if True, normalise the frequency response.
  
          .. plot::
              :width: 80%
              :include-source:
  
              from spectrum.window import Window
              w = Window(64, name='hamming')
              w.plot_frequencies()