.. _I3GenieSystWeightTracReader:

I3GenieSystWeightTracReader
===========================

This module converts a list of GENIE ReWeight output root files to a dictionary 
with arrays of corresponding systematic weights for each event. Can convert 
systematic weights with arbitrary number of tweak dials (tweak dials are not saved).

.. caution::

   Assumes that input files are produced for the same sequence of events as 
   in :ref:`I3GenieTracReader` module. Event numbers 
   are checked but there are no way to justify that particular ``grwght1p`` 
   output file was produced for a given GHEP file.

Systematic weights reading module is separated from I3GenieTracReader because 
in newer versions of GENIE (>=v3) ReWeight and Generator are different products.

Example usage
^^^^^^^^^^^^^

.. code-block:: python

        tray.AddModule(I3GenieSystWeightTracReader,
                       SystWghtFileNameList  = ['systw.NuMu.A.1400002.MaCCRES.root', 
		                                'systw.NuMu.A.1400002.MaCCQE.root'],
                       SystWghtDictName      = "SystWghtDictName")

Signature
^^^^^^^^^

.. autoclass:: icecube.genie_reader.I3GenieSystWeightTracReader

       **Methods:**
       
	       .. automethod:: icecube.genie_reader.I3GenieSystWeightTracReader.Configure
	       .. automethod:: icecube.genie_reader.I3GenieSystWeightTracReader.get_systematic
	       .. automethod:: icecube.genie_reader.I3GenieSystWeightTracReader.DAQ
	       .. automethod:: icecube.genie_reader.I3GenieSystWeightTracReader.Finish

Output object
^^^^^^^^^^^^^

I3GenieSystWeightTracReader produces only one type of objects:

1. ``I3GenieSystWeightDict`` (Q-Frame)

   Dictionary (:cpp:type:`I3MapStringVectorDouble`) which has an entry for each of 
   the systematics from the files specified in SystWghtFileNameList. Name of 
   a systematic is a key, which corresponds to an array of systematic 
   weights. Example:

   .. code-block:: none

      I3GenieSystWeightDict [I3Map<string, vector<double> >]:
      [rw_AhtBY => [1, 1, 1, 1],
      rw_BhtBY => [1, 1, 1, 1],
      rw_CV1uBY => [1, 1, 1, 1],
      rw_CV2uBY => [1, 1, 1, 1],
      rw_MaCCQE => [1, 1, 1, 1],
      rw_MaCCRES => [0.131828, 0.197077, 0.316496, 0.360967],
      rw_MaCOHpi => [1, 1, 1, 1],
      rw_MaNCEL => [1, 1, 1, 1],
      rw_MaNCRES => [1, 1, 1, 1]]