.. |clsPP| replace:: :class:`PlasmaParameter 1205 <pyana.pep.mhddata.PlasmaParameter1205>`

.. _plasmaparameterjia:

==============================
Plasma parameter near Ganymede
==============================

Xianzhe Jia provided his MHD simulated plasma paramters for PEP analysis.

The data file is stored in ``MHD_PlasmaParameters_3Rg_XianzheJia.mat`` file.
The file is not in the pyana repository, and should be prepared separately.

File format
===========
File is provided in the matlab format.
I do not plan to convert it to any other formats (text, idl or python pickle).
Use ``scipy.io.loadmat`` to load.  Also, :mod:`pyana.pep.mhddata` provides
the class |clsPP| as an adapter.


Detailed look into file structure
=================================

After reading the matlab formatted file, you will get a dictionary.

The dictionary has keys as:

'X'
        ``x`` coordinates. Unit of Ganymede radius, 1Rg = 2631.4 km.

'Y'
        ``y`` coordinates

'Z'
        ``z`` coordinates

'N'
        Density with the unit of /cm-3

'Vx'
        ``x``-component of velocity with the unit of km/s

'Vy'
        ``y``-component of velocity.

'Vz'
        ``z`` coordinates

'Pth'
        Thermal pressure with the unit of nPa.

'T'
        Temperature with the unit of eV.

All the quantities has (8000000, 1) shape. In reality, the data is organized
in 3-D cartesian grid.  Z is the first to rotate, Y follows and then, X.
Reshape would work well.  Each coordinate forms 200 data point.

Using the above information we will get the data dimension to 3-D in a straightforward way.

.. code-block:: py

        x = dat['X'].reshape((200, 200, 200))

The order of the argument is x, y, z.  (x[:, 0, 0] == x[:, iy, iz] for arbitrary iy and iz)


The coordinate system
=====================

GPHIO system is applied.  This is defined like:

x-axis
        The direction of the corotation flow

y-axis
        +Y points towards Jupiter

z-axis
        +Z is aligned with Jupiter's rotation axis


Implementation
==============

The class |clsPP| implements the data file maneuvour.