code: def read_dig_dat(fname):
      r"""Read electrode positions from a ``*.dat`` file.
  
      .. Warning::
          This function was implemented based on ``*.dat`` files available from
          `Compumedics <https://compumedicsneuroscan.com>`__ and might not work
          as expected with novel files. If it does not read your files correctly
          please contact the MNE-Python developers.
  
      Parameters
      ----------
      fname : path-like
          File from which to read electrode locations.
  
      Returns
      -------
      montage : DigMontage
          The montage.
  
      See Also
      --------
      read_dig_captrak
      read_dig_dat
      read_dig_egi
      read_dig_fif
      read_dig_hpts
      read_dig_localite
      read_dig_polhemus_isotrak
      make_dig_montage
  
      Notes
      -----
      ``*.dat`` files are plain text files and can be inspected and amended with
      a plain text editor.
      """
      from ._standard_montage_utils import _check_dupes_odict
  
      fname = _check_fname(fname, overwrite="read", must_exist=True)
  
      with open(fname) as fid:
          lines = fid.readlines()
  
      ch_names, poss = list(), list()
      nasion = lpa = rpa = None
      for i, line in enumerate(lines):
          items = line.split()
          if not items:
              continue
          elif len(items) != 5:
              raise ValueError(
                  f"Error reading {fname}, line {i} has unexpected number of entries:\n"
                  f"{line.rstrip()}"
              )
          num = items[1]
          if num == "67":
              continue  # centroid
          pos = np.array([float(item) for item in items[2:]])
          if num == "78":
              nasion = pos
          elif num == "76":
              lpa = pos
          elif num == "82":
              rpa = pos
          else:
              ch_names.append(items[0])
              poss.append(pos)
      electrodes = _check_dupes_odict(ch_names, poss)
      return make_dig_montage(electrodes, nasion, lpa, rpa)
  
imports: import os.path
  import re
  from collections import OrderedDict
  from copy import deepcopy
  from dataclasses import dataclass
  import numpy
  from .._fiff._digitization import _coord_frame_const, _count_points_by_type, _ensure_fiducials_head, _format_dig_points, _get_data_as_dict_from_dig, _get_dig_eeg, _get_fid_coords, _make_dig_points, _read_dig_fif, write_dig
  from .._fiff.constants import CHANNEL_LOC_ALIASES, FIFF
  from .._fiff.meas_info import create_info
  from .._fiff.open import fiff_open
  from .._fiff.pick import _picks_to_idx, channel_type, pick_types
  from .._freesurfer import get_mni_fiducials
  from ..defaults import HEAD_SIZE_DEFAULT
  from ..transforms import Transform, _ensure_trans, _fit_matched_points, _frame_to_str, _quat_to_affine, _sph_to_cart, _topo_to_sph, _verbose_frames, apply_trans, get_ras_to_neuromag_trans
  from ..utils import _check_fname, _check_option, _on_missing, _pl, _validate_type, copy_function_doc_to_method_doc, fill_doc, verbose, warn
  from ..utils.docs import docdict
  from ..viz import plot_montage
  from ._dig_montage_utils import _parse_brainvision_dig_montage, _read_dig_montage_egi
label_desc: Use image node_id 6 for calling a global function with example usage: read_dig_dat(fname) and returns: make_dig_montage