Introduction
============

The purpose of the |namespec| Specification is to provide a standard for
recording and recovering computer data of electromagnetic simulations.

A few well established data format already exist, we can quote :

* CGNS (CFD General Notation System, http://cgns.sourceforge.net/) is
  recommended for computational fluid dynamics problems (CFD). That's
  why a lot of electromagnetic concepts are missing
* SILO (a mesh and field I/O library and scientific database
  https://wci.llnl.gov/codes/silo/)
* MED (in french "Modélisation et Échanges de Données"
  http://www.code-aster.org/outils/med/), it is
  the SALOME's data format
  (http://www.salome-platform.org/home/presentation/overview/).
  Like CGNS, SALOME provides tools for CFD
  simulation and aren't adapted to the electromagnetism domain
* netCDF (http://www.unidata.ucar.edu/software/netcdf/)

Besides, |namespec| Specification is closely related to the |quercy| Platform.
|quercy| is a software platform aiming at :

 * Providing knowledge management capabilities
 * Providing pre and post processing tools
 * Integrating scientific softwares
 * Managing software execution

CGNS, SILO and MED specifications give a standard way of describing physical
models,
mesh definition and many physical concepts. Softwares that can express
their native data in CGNS
vocabulary are good "customers" for the specification, for data that can not
be correctly expressed CGNS offers a "user variable" notion. But for other
softwares handling complex structures stranger to the specification, there
is no way to use the existing format, even by part.

|quercy| Platform expresses data in the form of objects named "infotype",
it is possible to add new infotype to the platform and this infotype have to
be converted into equivalent concepts into |namespec|. So, |namespec| must be
sufficiently flexible to express unknown data coming from the new infotypes.
This can not be done with CGNS or MED.

The manner |namespec| accomplishes this task is described is the document.

Basically, |namespec| specification can express all sort of electromagnetic
data, the most important are :

 * Mesh (unstructured or structured);

 * Numerical array data;
 
 * Material models

 * Network and transmission line;

 * Electromagnetic sources

This document covers all the aspects of the |namespec| specification.

.. note::

    |namespec| is largely inspired from the Amelet project 
    (http://www.predit.prd.fr/predit3/syntheseProjet.fo?inCde=22740)