General aspects of PyX

The name of the game

Originally, the name PyX was constructed as a combination of Postscript, i.e. the first output format supported by PyX, Python, i.e. the language in which PyX is written, and TeX, i.e. the program which PyX uses for typesetting purposes. Actually, the title of this question is a tribute to TeX because it is taken from the first chapter of the TeX book [1] where the origin of the name TeX and its pronunciation are explained.

Despite the ties between TeX and PyX, their pronunciation is quite different. According to the developers of PyX, it should be pronounced as [pʏks]. Please do not pronounce it as [pʏx] or [pʏç].

Where do I get the latest version of PyX?

The current release of PyX (as well as older ones) is freely available from http://pyx.sourceforge.net where also a subversion repository with the latest patches can be found. In addition, PyX is registered on the Python Package Index at https://pypi.python.org/pypi/PyX and can be installed by easy_install and pip. However, the release files are not hosted on PyPI itself and for future versions of pip you need to allow external installation by --allow-external pyx. Please see the pip documentation for details.

Possibly older versions of PyX are also available as package for various Linux distributions: see, for instance, http://packages.debian.org/testing/python-pyx for information on the PyX package in Debian GNU/Linux or http://packages.ubuntu.com/raring/python-pyx for Ubuntu.

PyX has no dependencies on other Python packages.

How can I determine the version of PyX running on my machine?

Start a python session (usually by typing python at the system prompt) and then type the following two commands (>>> is the python prompt)

>>> import pyx
>>> pyx.__version__

Note that there are two underscores before and after version.

How can I access older versions of PyX?

There are reasons which might make it necessary to use older versions of PyX. If you are using Python 2 you will need PyX version 0.12.1 or earlier (see Under which versions of Python will PyX run?). Furthermore, as at present it is not guaranteed that PyX is backward compatible, it may be desirable to access an older version of PyX instead of adapting older code to a more recent version of PyX. In order to do that, one needs the corresponding PyX package (see Where do I get the latest version of PyX? if you need to download it), which should be unpacked below a directory, e.g. /home/xyz/Python, where you want to keep the various PyX versions. This will result in a subdirectory with a name like PyX-0.13 which contains the contents of the corresponding package. You can then ask Python to first look in the appropriate directory before looking for the current version of PyX by inserting the following code (appropriately modified according to your needs) at the beginning of your program before importing the PyX module:

import sys
sys.path.insert(0, "/home/xyz/Python/PyX-0.13")

Including appropriate lines even if the current version of PyX is used, might turn out to be helpful when the current version has become an old version (unless you have no difficulties determining the PyX version by looking at your code).

If your operating system supports path expansion, you might use as an alternative:

import sys, os
sys.path.insert(0, os.path.expanduser("~/Python/PyX-0.13"))

which will expand the tilde to your home directory.

Does PyX run under my favorite operating system?

Yes, if you have installed Python (What is Python?) and TeX (What is TeX/LaTeX and why do I need it?). Both are available for a large variety of operating systems so chances are pretty good that you will get PyX to work on your system.

Under which versions of Python will PyX run?

Starting with version 0.13, PyX requires Python 3.2 or higher. If you still need to run PyX with Python 2, you should use version 0.12.1 which is designed to run with Python 2.3 up to 2.7.

The version of your Python interpreter can be determined by calling it with the option -V. Alternatively, you can simply start the interpreter and take a look at the startup message. Note that there may be different versions of Python installed on your system at the same time. The default Python version need not be the same for all users.

Does PyX provide a GUI to view the produced image?

No, PyX itself does not provide a means to view the produced image. The result of a PyX run is an EPS (= Encapsulated PostScript) file, a PS (= PostScript) file or a PDF (= Portable Document Format) file, which can be viewed, printed or imported into other applications.

There are several means of viewing PS and EPS files. A common way would be to use ghostview which provides a user interface to the PostScript interpreter ghostscript. More information about this software, which is available for a variety of platforms, can be found at http://www.cs.wisc.edu/~ghost/. If you do not own a printer which is capable of printing PostScript files directly, ghostscript may also be useful to translate PS and EPS files produced by PyX into something your printer will understand.

PDF files can be viewed by means of the Adobe Reader ® available from http://www.adobe.com/products/acrobat/readstep2.html. On systems running X11, xpdf might be an alternative. It is available from http://www.foolabs.com/xpdf/.

If you want to do interactive development of a PyX graphics, you might consider to use an IPython notebook (see Will I be able to embed PyX graphics output into an IPython notebook?).

Will I be able to embed PyX graphics output into an IPython notebook?

Yes, PyX canvas object and objects inheriting from the canvas class, in particular graphs and text, can be embedded into an IPython notebook. Suppose you have a canvas object called c on which you have done some drawing. Then entering c in an IPython notebook cell and executing that cell will automatically produce a PNG representation and embed it into the notebook. For more information on IPython and working with its notebooks see http://www.ipython.org/.

I am a Gnuplot user and want to try PyX. Where can I get some help?

There exists a tutorial by Titus Winters which explains how to perform standard Gnuplot tasks with PyX. The tutorial can be found at http://www.cs.ucr.edu/~titus/pyxTutorial/.

Where can I get help if my question is not answered in this FAQ?

The PyX sources contain a reference manual which is also available online at http://pyx.sourceforge.net/manual/. Furthermore, there exists a set of examples demonstrating various features of PyX, which is available in the sources or can be browsed at http://pyx.sourceforge.net/examples.html. If the feature you are looking for is among them, using the appropriate part of the example code or adapting it for your purposes may help.

There is also a user discussion list about PyX which you can subscribe to at http://lists.sourceforge.net/lists/listinfo/pyx-user. The archive of the discussion list is available at http://sourceforge.net/mailarchive/forum.php?forum_name=pyx-user.

Finally, it might be worth checking http://pyx.sourceforge.net/pyxfaq.pdf for an updated version of this FAQ.

[1]D.Knuth, The TeX book (Addison-Wesley, 1984)