JohnLangford/vowpal_wabbit — pull request #29 by petricek (2012-03-31 01:11:31+00:00)
Title: Added a --keep option

The option --keep is a natural counterpart to --ignore. It will use just the namespace(s) listed and ignore all others.

I find this handy when I have a file with lots of namespaces and features and I want to train a model with one namespace only as a sanity check. The same functionality can be achieved by adding --ignore for every namespace in the input but this results in a long command line and is error prone.