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Arlindo da Silva
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===================================== 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.
