Requirements
============

.. _software_reqs:

Software
---------

You need a Python interpreter and several add-on packages for
scientific computing. Modern Linux and OS X operating systems come
with Python pre-installed. However, it is recommended to freshly
install the appropriate versions manually; this is particularly true
for OS X, since we had bad experiences with broken Python versions
shipped by Apple.

-----------------------------------------------------------------------

**Install the following:**

.. note::

  **Windows users** should install the 32-bit versions of the packages
  listed below, even if they have a 64-bit system. This is because at
  the time of writing (|today|), no 32-bit binary packages of some
  dependencies are available for Windows.

1. `Python <http://www.python.org/download/releases/2.6.6/>`_ **version 2.6.6**
   (The currently available binary package for Numpy
   (1.5.0) does not install with Python 2.7)
2. `Numpy <http://sourceforge.net/projects/numpy/files/>`_ version 1.5.0 or later
3. `SciPy <http://sourceforge.net/projects/scipy/files/>`_ version 0.8.0 or later
4. `netcdf4-python <http://code.google.com/p/netcdf4-python/downloads/list>`_
   version 0.9.2 or later (netcdf4 is necessary for the netCDF output).
5. Not necessary but strongly recommended is the
   `ipython <http://ipython.scipy.org/moin/Download>`_ interactive shell.
6. Not necessary but recommended to plot results is `matplotlib
   <http://matplotlib.sourceforge.net/>`_.
7. To visualized output in netCDF format, I recommend `Panoply
   <http://www.giss.nasa.gov/tools/panoply/>`_.

------------------------------------------------------------------------

.. note::

     **A one-stop solution** to set up the necessary components (and much
     more) for any operating system is the `Enthought Python Distribution
     (EPD) <http://www.enthought.com/products/edudownload.php>`_. It is
     provided for free under the "academic license".  In case the website
     does not recognize you as an academic user, look `here
     <http://www.enthought.com/repo/.hide_epd_installers/>`_.

.. note::

    The download of EPD is large (>200 MB) and their website is sloow!

.. note::
  
    **Windows users** should install the 32-bit version of EPD, even
    if they have a 64-bit system. This is because at the time of
    writing (|today|), the 64-bit EPD does not contain the module
    necessary for netCDF output.

.. note::

    **Users of Debian or Ubuntu** may install the necessary dependencies
    via their package management system.

------------------------------------------------------------------------

We have tested the functionality of the installation of the
dependencies described above for Windows XP, for Ubuntu 10.04 (Lucid
Lynx") and for Debian 6.0 ("Squeeze"). Any reports about success or
failure for other operating systems is highly appreciated. Drop me an
email.

Hardware
--------

Any more or less modern desktop PC should do. Please let me know if
you run into problems that appear to be caused by a lack of computer
ressources.