.. _fwflag_add_message_id:
==================
--add_message_id
==================
Switch
======

--add_message_id MESSAGE_FILE STATE_FILE_GZ

Description
===========

Rewrites a Mallet LDA state file's numeric document index back into real group ids, by cross-referencing the joined-feature-lines file used to build the LDA model.

Argument and Default Value
==========================

Two file paths: the joined-feature-lines file (as written by :doc:`fwflag_print_joined_feature_lines`) and the gzipped Mallet state file. Default: ``None`` (not used directly).

Details
=======

Verified: this is normally triggered *automatically* by :doc:`fwflag_estimate_lda_topics` (which sets ``args.addmessageid = [joined_feature_lines_file, state_file]`` itself right after calling Mallet) — you don't need to pass it by hand in the common workflow. Despite the name, the id substituted in is whichever **group id** the feature table used (e.g. ``user_id``), not necessarily a literal message id — confirmed by running with a user-level feature table and seeing real ``user_id`` values appear in the rewritten state file's ``source`` column, in place of Mallet's internal sequential document index.

Other Switches
==============

Optional Switches:

* :doc:`fwflag_estimate_lda_topics` (the usual way this gets triggered)

Example Commands
================

Using the packaged ``dla_tutorial`` dataset (see :doc:`../../tutorials/tut_dla` and :doc:`../../tutorials/tut_lda`) — verified end-to-end with real Mallet:

.. code-block:: bash

	dlatkInterface.py -d dla_tutorial -t msgs -c user_id -f 'feat$1gram$msgs$user_id' \
	--estimate_lda_topics --num_topics 20 --no_lda_lexicon \
	--mallet_path /opt/homebrew/bin/mallet --save_lda_files ./lda_out --num_lda_threads 2