docs: def summary(self):
          """ prints results of hotellings T2 """
          transform = self._catalog_object._transform
          if   transform == 'time':
              self._hotellings_time()
          elif transform == 'fourier':
              self._hotellings_fourier()
          elif transform == 'spectrogram':
              self._hotellings_spectrogram()
          elif transform == 'amplitude':
              self._hotellings_amplitude()
          elif transform == 'phase':
              self._hotellings_phase()
          else:
              raise ValueError("Unknown catalog transformation")
          # print out to terminal
          self._make_summary_tables()