docs: def syscal_save_to_config_txt(filename, configs, spacing=1):
      """Write configurations to a Syscal ascii file that can be read by the
      Electre Pro program.
  
      Parameters
      ----------
      filename: string
          output filename
      configs: numpy.ndarray
          Nx4 array with measurement configurations A-B-M-N
  
      """
      print('Number of measurements: ', configs.shape[0])
      number_of_electrodes = configs.max().astype(int)
  
      with open(filename, 'w') as fid:
          _syscal_write_electrode_coords(fid, spacing, number_of_electrodes)
          _syscal_write_quadpoles(fid, configs.astype(int))