=====================================
PyGrADS - A Python Interface to GrADS
=====================================
Author:
Arlindo da Silva <dasilva@opengrads.org>
License:
GNU Public License Version 2
Overview
========
This package implements a Python_ interface to GrADS_ by means of
bi-directional pipes. The following modules are provided:
gacore
The module *gacore* provides the basic GrADS client class which
allows you to start GrADS, send commands to it and to retrieve the
text output produced by *grads* in response to such command. This is
a Pure Python module, although it requires the GrADS binaries to
have been installed on your system.
ganum
If you have NumPy installed, the module *ganum* will be loaded.
This module extends the GrADS client class in *gacore* by providing
methods for exchanging n-dimensional NumPy array data between Python
and GrADS. It also provides methods for computing EOF and least
square estimation.
galab
If PyLab/Matplotlib/Basemap is available, the module *galab* is
loaded. This module adds Matplotlib/Basemap specific methods for
contours, images and other graphical functionality. This class
provides high level methods operating directly on GrADS expressions
(or *fields*) while retaining all the configurability that
Matplotlib has to offer.
gaya
If MayaVi is available, the module *gaya* is loaded. This module
adds MayaVi specific methods for 3D visualization. As in *galab*,
the main design philosophy is to use the GrADS dimension environment
to derive sensible defaults for the high level graphical commands,
while retaining most of MayaVi configurability.
gahandle
This module provides a simple container class to collect output for
query() operations.
gacm
This modules provides additional colormaps, as well as an extension
of the *Colormaps* class which allows for the definition of color
look-up takes with an alpha channel. It also extends the
*LinearSegmentedColormap* with the ability of create derived color
tables which are either reversed or provide an arbitrary scaling by
means of a lambda function.
numtypes
This module defines GaField, a class for representing GrADS
variables in Python. It consists of a NumPy masked array with a
*grid* containing coordinate/dimension information attached to it.
pygrads
The script *pygrads* is a wrapper script which starts IPython
with a number of aliases and customizations convenient for
interactive GrADS work. In particular, it starts PyLab bringing
together all the GrADS and Matplotlib capabilities, if available.
For additional information consult the PyGrADS_ documentation.
Requirements
============
This release has been verified to work with the Enthought Python
Distribution (EPD) Version 7.1-2, althought it should also work with a
generic python distribution.The actual packages needed depends on the
functionality that you require:
gacore
For the basic features in *gacore* you only need Python_ or Jython_. I've
tested it on C Python v2.3 and newer, but it may work in older
versions as well. It also runs on Jython v2.2. There is some chance that
*gacore* works with IronPython as well, but I haven't tested it yet.
ganum
You will need NumPy_. This module does not work with Jython_.
galab
This requires Pylab and Matplotlib_, in addition to the Basemap_
toolkit. For working with images you would need PIL_, the Python
Imaging Library. This module does not work with Jython_.
gaya
Requires MayaVi and all the requirements for *galab*.
gacm
Same dependencies of *galab*, but now PIL_ is required. This module
does not work with Jython_.
pygrads, ipygrads
The script *pygrads* is a wrapper around IPython_, so you will need to
install it first. The module *ipygrads* implements some *magic
commands* for IPython providing convenient shorthands for interactive
grads work. This module does not work with Jython_ v2.2 because IPython
is not available (but possibly will in Jython v2.5).
When you import package *grads* the following attributes are defined,
depending on which of the modules were successfully imported:
HAS_GALAB, HAS_GANUM, HAS_GACM. An *ImportError* exception will be
raised if *gacore* cannot be imported. See `Useful Links` below for
the URL of the required packages.
Useful Links
============
.. _Basemaps: http://www.scipy.org/Cookbook/Matplotlib/Maps
.. _GrADS: http://grads.iges.org/grads
.. _Installation: http://docs.python.org/inst/inst.html
.. _IPython: http://ipython.scipy.org/moin/
.. _Jython: http://www.jython.org/
.. _Matplotlib: http://matplotlib.sourceforge.net/
.. _NumPy: http://numpy.scipy.org/
.. _OpenGrADS: http://opengrads.org
.. _PIL: http://www.pythonware.com/products/pil/
.. _PyGrADS: http://opengrads.org/wiki/index.php?title=Python_Interface_to_GrADS
.. _Python: http://www.python.org
Installation
============
See file INSTALL.
License Terms
=============
See file COPYING.
