code: def amplitude_from_polarizations(h_plus, h_cross):
      
      amp = (h_plus.squared_norm() + h_cross.squared_norm()) ** (0.5)
      return TimeSeries(amp, delta_t=h_plus.delta_t, epoch=h_plus.start_time)
docs: Return gravitational wave amplitude
  
      Return the gravitation-wave amplitude from the h_plus and h_cross
      polarizations of the waveform.
  
      Parameters
      ----------
      h_plus : TimeSeries
          An PyCBC TmeSeries vector that contains the plus polarization of the
          gravitational waveform.
      h_cross : TimeSeries
          A PyCBC TmeSeries vector that contains the cross polarization of the
          gravitational waveform.
  
      Returns
      -------
      GWAmplitude : TimeSeries
          A TimeSeries containing the gravitational wave amplitude.
  
      Examples
      --------
      >>> from pycbc.waveform import get_td_waveform, phase_from_polarizations
      >>> hp, hc = get_td_waveform(approximant="TaylorT4", mass1=10, mass2=10,
                           f_lower=30, delta_t=1.0/4096)
      >>> amp = amplitude_from_polarizations(hp, hc)