.. _fwflag_categories:
=============
--categories
=============
Switch
======

--categories CATEGORY [CATEGORY ...]

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

Restricts a lexicon-driven black/white list (see :doc:`fwflag_blacklist`/:doc:`fwflag_whitelist`) to specific categories from the lexicon table given by :doc:`fwflag_l`.

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

One or more category names/ids as they appear in the lexicon table's ``category`` column. Default: none (all categories used).

Details
=======

Verified: used together with :doc:`fwflag_l` and :doc:`fwflag_whitelist` (or :doc:`fwflag_blacklist`), this builds a white/black list of the individual *words* belonging to the given lexicon categories, for filtering a word/ngram-level feature table (e.g. ``feat$1gram$...``) — not for filtering an already-built category-level table (``feat$cat_...``), which has no use for this switch since its features already are the category names. Pass ``*`` to mean all categories in the lexicon table.

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

Required Switches:

* :doc:`fwflag_l` LEX_TABLE
* :doc:`fwflag_whitelist` or :doc:`fwflag_blacklist`

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

.. code-block:: bash

	dlatkInterface.py -d dla_tutorial -t msgs -c user_id -f 'feat$1gram$msgs$user_id$16to16' \
	--outcome_table blog_outcomes --outcomes age -l met_a30_2000_cp --categories 344 --whitelist --correlate