fluidsim 0.3.1

Framework for studying fluid dynamics with simulations.

Fluidsim is an extensible framework for studying fluid dynamics with numerical
simulations using Python. Fluidsim is an object-oriented library to develop
solvers (mainly using pseudo-spectral methods) by writing mainly Python code.
The result is **very efficient** even compared to a pure Fortran or C++ code
since the time-consuming tasks are performed by optimized compiled functions.

**Documentation**: https://fluidsim.readthedocs.io

Getting started
---------------
To try fluidsim without installation: |binder|

For a **basic installation** it should be sufficient to run::

pip install fluidsim --no-cache-dir [--user]

Add ``--user`` flag if you do not have permission to write in the directory of
the python executable and you don't want to / can't setup a virtual environment
or use pyenv or conda.

Installation
------------

To take full advantage of fluidsim, consider installing the following
(optional) dependencies and configurations before installing fluidsim. Click on
the links to know more:

1. OpenMPI or equivalent
2. FFT libraries such as MPI-enabled FFTW (for 2D and 3D solvers) and P3DFFT,
PFFT (for 3D solvers) either using a package manager or `from source
<https://fluidfft.readthedocs.io/en/latest/install/fft_libs.html>`__
3. Install optional Python `package dependencies
<https://fluidsim.readthedocs.io/en/latest/install.html#dependencies>`__
4. `A C++11 compiler and BLAS
libraries <https://pythran.readthedocs.io/en/latest/#installation>`__ and
`configure
<https://fluidsim.readthedocs.io/en/latest/install.html#dependencies>`__
``~/.pythranrc`` to customize compilation of Pythran extensions
5. `Configure
<https://fluidfft.readthedocs.io/en/latest/install.html#basic-installation-with-pip>`__
``~/.fluidfft-site.cfg`` to detect the FFT libraries and install
``fluidfft``

**Note**: Detailed instructions to install the above dependencies using Anaconda
/ Miniconda or in a specific operating system such as Ubuntu, macOS etc. can be
found `here
<https://fluiddyn.readthedocs.io/en/latest/get_good_Python_env.html>`__.

You can get the source code from `Bitbucket
<https://bitbucket.org/fluiddyn/fluidsim>`__ or from `the Python
Package Index <https://pypi.python.org/pypi/fluidsim/>`__.
The development mode is often useful if you intend to modify fluidsim . From
the root directory::

python setup.py develop

Tests
-----
After installing fluidsim run the tests to ensure everything works::

fluidsim-test
mpirun -np 2 fluidsim-test

How does it work?
-----------------
Fluidsim is a `HPC <https://en.wikipedia.org/wiki/High-performance_computing>`_
code. It is part of the wider project `FluidDyn
<https://pypi.python.org/pypi/fluiddyn/>`_ and its pseudospectral solvers rely
on the library `fluidfft <http://fluidfft.readthedocs.io>`_ to use very
efficient FFT libraries. Fluidfft is written in C++, Cython and Python.
Fluidfft and fluidsim take advantage of `Pythran
<https://github.com/serge-sans-paille/pythran>`_, an ahead-of-time compiler
which produces very efficient binaries by compiling Python via C++11.

An advantage of a CFD code written mostly in Python is that, to run simulations
and analyze the results, the users communicate (possibly interactively)
together and with the machine with Python, which is nowadays among the best
languages to do these tasks. Moreover, it is much simpler and faster than with
pure Fortran or C++ codes to add any complicated analysis or to write a
modified solver. Fluidsim can also be used to extend existing solvers with
Python interfaces such as `Basilisk <http://basilisk.fr>`__.

We have created fluidsim to be **easy and nice to use and to develop**,
**efficient** and **robust**.

*Keywords and ambitions*: fluid dynamics research with Python (>=3.6);
modular, object-oriented, collaborative, tested and documented, free and
open-source software.

License
-------

FluidDyn is distributed under the CeCILL_ License, a GPL compatible
french license.

.. _CeCILL: http://www.cecill.info/index.en.html