Prepare the executable:
==========================

CHIMERE is a heavy and complex code written in Fortran90.
It is thus required to compile it before running.
This can be done either manually or automatically.

If you are using the CIF for the first time on your cluster,
it is recommended to check manually that the compiling works properly.
With the manual compilation, the executable can be prepared once for all 
outside the CIF with the following steps and then stored
in a reference directory for later use.

.. warning::

    CHIMERE is a research code under developments. It may happen that the source code is changed
    to fix bugs or add new features. When a working case with CHIMERE suddenly stops working after a pycif
    update, please force re-compiling the executables.

Manual computation
--------------------------


Detailed instructions are given :doc:`here </documentation/doc-models/chimere/compiling>`

In directory :bash:`model_sources/chimereGES`, compile the fortran chemistry-transport model:

.. code-block:: bash

    ./compile_chimere -m D

Option `-m D` indicates that the forward code is compiled.

In case of a previous compilation,

.. code-block:: bash

    ./compile_chimere -m D -d N -c Y

ensures that the new compilation starts from scratch. Option `-d N` indicates that the compiling mode is NOT for debugging.

⟹ check that you obtain an executable in sub-directory :bash:`src` named :bash:`fwdchimere.e`, about 2.5M in size.

Automatic computation
---------------------

It is also possible to opt for a compilation made by the CIF when required:
this is done by specifying the option :bash:`auto-recompile`
(and associated options :bash:`compile-mode` and :bash:`compile-clean`) in plugin
:doc:`model</documentation/plugins/models/chimere>` in the yaml (see details in :ref:`yml_section_model_chimere_fwd`).
In this case, no previous preparation of the executable is required.