incremental.howto.txt

用python实现的邮件过滤器

There are a few steps to doing incremental training tests:

1. Get your corpora.  It's best if they're contemporaneous
   and single source, because that makes it much easier to
   sequence and group them.  The corpora need to be in the
   good old familiar Data/{Ham,Spam}/{reservoir,Set*} tree.
   For my (Alex) purposes, I wrote the es2hs.py tool to grab
   stuff out of my real MH mail archive folders; other people
   may want some other method of getting the corpora into the
   tree.  If you're using Outlook, then the
   Outlook2000/export.py script is what you are after.

2. Sort and group the corpora.  When testing, messages will
   be processed in sorted order.  The messages should all
   have unique names with a group number and an id number
   separated by a dash (eg. 0123-004556).  I (Alex) wrote
   sort+group.py for this.  sort+group.py sorts the messages
   into chronological order (by topmost Received header) and
   then groups them by 24-hour period.  The group number (0123)
   is the number of full 24-hour periods that elapsed between
   the time this msg was received and the time the oldest msg
   found was received.  The id number (004556) is a unique
   0-based ordinal across all msgs seen, with 000000 given to
   the oldest msg found.

   With 1.0.x, note that this script will run through *all* the
   files in the Data directory, not just those in Data/Ham and
   Data/Spam.  With 1.1, only those specified in the
   ham_directories and spam_directories will be used, unless
   the -a option is used.

3. Distribute the corpora into multiple sets so you can do
   multiple similar runs to gauge validity of the results
   (similar to a cross-validation, but not really).  When
   testing, all but one set will be used for a particular
   run.  I personally use 5 sets.

   Distribution is done with mksets.py.  It will evenly
   distribute the corpora across the sets, keeping the
   groups evenly distributed, too.  You can specify the
   number of sets, limit the number of groups used (to
   make short runs), and limit the number of messages per
   group*set distributed (to simulate less mail per group,
   and thus get more fine-grained results).

4. Run incremental.py to actually process the messages in
   a training and testing run.  How training is done is
   determined by what regime you specify (regimes are
   defined in the regimes.py file; see the perfect and
   corrected classes for examples).  For large corpora,
   you may want to do the various set runs separately
   (by specifying the -s option), instead of building
   nsets classifiers all in parallel (memory usage can
   get high).

   Make sure to save the output of incremental.py into
   a file... by itself it's ugly, but postprocessing
   can make it useful.

5. Postprocess the incremental.py output.  I made mkgraph.py
   to do this, outputting datasets for plotmtv.  plotmtv is
   a really neat data visualization tool.  Use it.  Love it.
   XXX tools for Excel.

See dotest.sh for a sample of automating steps 4 & 5.