docs: def _get_tdm(self, m):
          """For a given model, return a tdMan instance
  
          Parameters
          ----------
          m : ndarray
              Model parameters (linear, ohm m)
          """
          m = np.atleast_2d(m)
          assert len(m.shape) == 2
          tdm = crtomo.tdMan(grid=self.grid, tempdir=self.tempdir)
          tdm.configs.add_to_configs(self.configs)
  
          pid_mag = tdm.parman.add_data(m[0, :])
          tdm.register_magnitude_model(pid_mag)
          if m.shape[0] == 2:
              pid_pha = tdm.parman.add_data(m[1, :])
          else:
              pid_pha = tdm.parman.add_data(np.zeros(m.shape[1]))
          tdm.register_phase_model(pid_pha)
          return tdm