docs: def load_crmod_config(self, filename):
          """Load a CRMod configuration file
  
          Parameters
          ----------
          filename: string
              absolute or relative path to a crmod config.dat file
  
          """
          with open(filename, 'r') as fid:
              nr_of_configs = int(fid.readline().strip())
              configs = np.loadtxt(fid)
              print('loaded configs:', configs.shape)
              if nr_of_configs != configs.shape[0]:
                  raise Exception(
                      'indicated number of measurements does not equal ' +
                      'to actual number of measurements')
              ABMN = self._crmod_to_abmn(configs[:, 0:2])
              self.configs = ABMN