atf format converter

Provides conversion between files in aft/xml format (file format for storing of measurement data, see http://www.asam.net) and "atf".

"atf" is a xml variant based on aft/xml but more suitable for xml processing for example xquery, xpath (see http://vcasterna.wordpress.com/2013/06/15/a-better-atfxml/)

In atf, xml query becomes simple:

e.g. navigation across parent/child relations:
subtests/subtest[name='run up']
With a given test instance being the context node this selects all subtests of a given instance name.

navigation across info relations:
id(channels/channel[name='Time']/local_columns/@refs)
With a given measurement instance being the context node this selects the local column of the time channel.

The program expects a list of file names. Files ending on atfx are converted to atf while those ending on atf are converted to atfx.