code: def get_xy_simple_dipole_dipole(dataframe, spacing=1, indices=None):
      
      if indices is None:
          indices = slice(None)
      abmn = dataframe.ix[indices, ['a', 'b', 'm', 'n']].values
      posx = np.mean(abmn[:, 0:4], axis=1)
      posz = np.abs(
          np.min(abmn[:, 0:2], axis=1) - np.max(abmn[:, 2:4], axis=1)
      ) * -0.192
  
      # scale the positions with the electrode spacing
      posx *= spacing
      posz *= spacing
      print(abmn.shape, posx.shape)
      print('posxz', np.vstack((abmn.T, posx, posz)).T)
      return posx, posz
docs: For each configuration indicated by the numerical index array, compute
      (x,z) pseudo locations based on the paper from XX.
  
      All positions are computed for indices=None.