CGNS
====

.. toctree::
   :maxdepth: 1
   :caption: Contents:

About
-----

`CGNS (CFD General Notation System) <https://cgns.github.io/>`_ is a library for reading and writing numerical simulation data in a portable, vendor-neutral format. It is widely used in the field of computational fluid dynamics (CFD) and other scientific simulations. For more information, visit the `official CGNS website <https://cgns.github.io/>`_.

CGNS is a standard for storing and exchanging numerical simulation data in a portable, vendor-neutral format. It is widely used in the field of computational fluid dynamics (CFD) and other scientific simulations.

.. note:: On Discoverer HPC, the CGNS library is a dependency to the VTK library. That way it supports the external packages compiled with LAMMPS.


Available versions
------------------

To view available zlib versions::

    $ module avail cgns

Build recipes and configuration details are maintained in our GitLab repository:

* `Build Recipes <https://gitlab.discoverer.bg/vkolev/recipes/-/tree/main/cgns>`_


Access to the CGNS library
--------------------------

To access the latest version of the CGNS library, load the module without specifying the version:

.. code:: bash

    $ module load cgns


In case you need to access a specific version of the CGNS library, you can specify the version:

.. code:: bash 

    $ module load cgns/<version>


Compiler support
----------------

We use the recent :doc:`llvm` to build the CGNS library code. We do not support any other compilers for that purpose. The `LLVM.org <https://llvm.org/>`_ compilers are the default compilers on Discoverer Petascale Supercomputer. Since the code of the library does not include Fortran, the compiled binaries are not Fortran-compatible and can be used with any other compiler collection.

Getting Help
------------

For additional assistance:

* See the :doc:`help` documentation