.. _ima_extra_contents:

=======================
IMA extra file contents
=======================

This section provides technical information about IMA extra file.

.. note::

        For users who wants to use the parameter file,
        refer to :mod:`irfpy.vima.imaextra` module.


IMA extra file
==============

IMA extra for VEX, or Andrei's file, can be read as follows.
Also, netCDF4 should be installed.

.. code-block:: sh

        pip install netcdf4

In addition, you may add the following setting into ``~/.irfpyrc``.

Start reading
-------------

To read the IMA EXTRA file, you can either specify the file name
of the 

.. code-block:: py

        >>> nc = irfpy.imacommon.imaextra2.ImaExtraFileCommon(fn)

Contents
--------

Dimensions and variables can be read

.. code-block:: py

        >>> print nc.dim.keys()
        [u'TimeLength', u'RmDim', u'AzPolDim', u'EnerDim', u'Time']
        >>> print nc.dim.vars()
        [u'AngTableN',
         u'HpSpec',
         u'ETableN',
         u'Pacc',
         u'RestRm',
         u'HeavySpec',
         u'StopTime',
         u'StartTime',
         u'Time',
         u'FracO2']

The dimensions are defined, for example,
/Volumes/scidata/data/venus/DD/NC/IMAEXTRA/imaextra20123640214.nc.gz

============= ============= ==================================
Name          Length        Content
============= ============= ==================================
TimeLength    17            Length of time expression.
RmDim         32            Mass ring number
AzPolDim      16            Azimuth/Elevation dimension
EnerDim       96            Energy dimension
Time          39 (variable) Time dimension
============= ============= ==================================

The variables are

============= ================== ==================================
Name          Length             Content
============= ================== ==================================
AngTableN     (39,)              ?
HpSpec        (39,16,96,16)      Proton's spectrum
ETableN       (39,)              ?
Pacc          (39,)              Post acceleration
RestRm        (39,16,96,16,32)   Rest matrix
HeavySpec     (39,16,96,16)      Heavy spectrum
StopTime      (17,)              Stop time (string array...)
StartTime     (17,)              Start time (string array...)
Time          (39,17)            Array of time
FracO2        (39,16,96)         ?
============= ================== ==================================

Time is a format of 17 length character.
You may use :func:`irfpy.asperacommon.dd.ncdfdd2datetime` function to 
convert to datetime instance.

Note that these entries are slighly different from MEX/IMAEXTRA file.