IP[y] Extensions (IPyXt)

Some extensions for the IPython interactive computing environment (especially for qtconsole and notebook mode).

sympyprt (new version)

This version has a completely rewritten TeX2 class which does not use tempfiles anymore. The old version was renamed to sympyprt_old. Some minor changes concern the interactive help strings. For details consult the test_sympyprt.py, sympyprt_howto.maff and the *.html files. The license was changed from BSD(2) to BSD(0), i.e. no restrictions at all.

This is a single file (sympyprt.py) extension for SymPy - the Python library for symbolic mathematics.

Purpose

sympyprt is a SymPy printer extension which renders the output (provided that you are using ipython qtconsole or ipython notebook) of SymPy to a LaTeX compiled inline image.

Prerequisites

A complete IPython installation (details @ ipython.org):

• IPython 0.11+ (with PyQT4, ZMQ)
• tornado (IPython 0.12+, for notebook)
• LaTeX distribution with latex and dvipng commands (in the system path!)
• Several addtional LaTeX packages:
  • breqn
  • amssymb
  • amsmath
  • bm (from here: old version only)
  • color
  • flexisym

Some are not really necessary and can be removed by editing the code (TeX2).

The breqn package is used to split very long output.

Installation

Copy the file sympyprt.py (possibly after editing) into the IPython extension directory.
Usually: site-packages/IPython/extensions. For Mac users see [issue #1] (nilqed#1 "Issue #1"). BTW the script was not tested on OSX. Consult the IPython user manual in case of difficulties to find the extension directory.

Usage

Load the extension with the IPython magic:

%load_ext sympyprt

This defines also a magic command %sympyprt to control the TeX rendering:

%sympyprt on|off ................... turn rendering on/off
%sympyprt help ..................... show a help text
%sympyprt use simple|mplib|latex ... set the rendering method
%sympyprt <parameter> <value> ...... change a parameter

Some examples:

%sympyprt fontsize 12        ;; set font size to 12 pt
%sympyprt textcolor Red      ;; set text color to red
%sympyprt backcolor Yellow   ;; set background color to yellow
                                (default is Transparent)
%sympyprt resolution 150     ;; set image resolution to 150 dpi
%sympyprt imagsize bbox      ;; set image size to bbox = bounding box
                                useful if offset is used
%sympyprt imagesize tight    ;; no border around content (tight). This is
                                the default.
%sympyprt imagesize 2cm,3cm  ;; set the image size to 2x3 cm. There must
                                be no whitespace within the dimension pair.
%sympyprt offset -2cm,-1cm   ;; set the offset of the content within the
                                image.
%sympyprt reset config       ;; reset config to factory settings
%sympyprt reset cache        ;; clear cache and delete all png files from
                                the temp dir.
%sympyprt matrix v           ;; set matrix border: p,v,b,V,B,small
%sympyprt breqn on           ;; use the breqn package: on/off
@sympyprt mode equation      ;; choose mode: inline, equation, equation*   

Advanced usage

There is a picture cache avoiding rendering the same output again and again (i.e inspecting the history).

To access the internals do as follows (for example):

from sympyprt import *
cfg ...................... show configuration dictionary
                           values may be changed directly or with
                           the set_<parameter> functions.
ObjCache ................. display the object cache (this is a dict)
                           full access
                           ObjCache[id(<sympy_object>)] -> TeX instance
                           -> can be re-rendered with different parameters
                           or deleted ....
                           There are also exposed manipulation functions
                           like putObj, getObj, hasObj, getPNG ...
cfg_reset ................ reset the cfg dict to factory settings

TeX0, TeX1, TeX2 ......... To test the rendering one can use the different
                           classes as follows, e.g.:
                           p = TeX2('$$\hbar^2$$') --> p

Example:

for x in ObjCache.values():
  print x.tex # the TeX code of the object

for x in ObjCache.values():
  print x.pngfile # the png file names in the temp dir

from sympyprt import TeX2 as tex
tex(r'This text was rendered with \LaTeX')

Notes

Magic name:

If one prefers another name for the %sympyprt magic, change the global variable _magic in the code below.

if the latex method is used all the png images are stored in the user's temp directory. The LaTeX source and aux files will be cleared (provided that cleanup is True) but not the images. Either use the remove_pngfile method of the TeX2 class or clear the temp directory manually.

NT: !dir %temp% -> show the content of the temp dir

Many (if not most) objects are cached with its 'id'. When typing

_n ([n] = IPy output number) a cached image will be shown. There
are several methods to redraw the image:

 1. delete it from the cache
 2. get the instance from the cache and use its render() method
 3. delete the original object, so that simpy creates a new one (id)

Sample output

QT sample (HTML
Notebook sample (ipynb)

Credits

based on ipython/extensions/sympyprinting.py by Brian Granger  
dvipng 1.XX Copyright 2002-2008 Jan-Ake Larsson