MathModePlugin

Include LaTeX formatted math in your Foswiki pages

Description

This plugin allows you to include mathematics in a topic, with a format very similar to LaTeX. The external program latex2html is used to generate gif (or png) images from the math markup, and the image is then included in the page. The first time a particular expression is rendered, you will notice a lag as latex2html is being run on the server. Once rendered, the image is saved as an attached file for the page, so subsequent viewings will not require re-renders. When you remove a math expression from a page, its image is deleted.

Note that this plugin is called MathModePlugin, not LaTeXPlugin, because the only piece of LaTeX implemented is rendering of images of mathematics.

Syntax Rules

<latex [attr="value"]* > formula </latex>

generates an image from the contained formula. In addition attribute-value pairs may be specified that are passed to the resulting img html tag. The only exeptions are the following attributes which take effect in the latex rendering pipeline:

• size: the latex font size; possible values are tiny, scriptsize, footnotesize, small, normalsize, large, Large, LARGE, huge or Huge; defaults to %LATEXFONTSIZE%
• color: the foreground color of the formula; defaults to %LATEXFGCOLOR%
• bgcolor: the background color; defaults to %LATEXBGCOLOR%

The formula will be displayed using a math latex environment by default. If the formula contains a latex linebreak (\\) then a multline environment of amsmath is used instead. If the formula contains an alignment sequence (& = &) then an eqnarray environment is used.

Note that the old notation using %$formula$% and %\[formula\]% is still supported but are deprecated.

If you might want to recompute the images cached for the current page then append ?refresh=on to its url, e.g. click here to refresh the formulas in the examples below.

Examples

The following will only display correctly if this plugin is installed and configured correctly.

<latex title="this is an example">
  \int_{-\infty}^\infty e^{-\alpha x^2} dx = \sqrt{\frac{\pi}{\alpha}}
</latex>

<latex>
  {\cal P} & = & \{f_1, f_2, \ldots, f_m\} \\
  {\cal C} & = & \{c_1, c_2, \ldots, c_m\} \\
  {\cal N} & = & \{n_1, n_2, \ldots, n_m\}
</latex>

<latex title="Calligraphics" color="orange">
  \cal
  A, B, C, D, E, F, G, H, I, J, K, L, M, \\
  \cal
  N, O, P, Q, R, S, T, U, V, W, X, Y, Z
</latex>

<latex>
  \sum_{i_1, i_2, \ldots, i_n} \pi * i + \sigma
</latex>

This is new inline test.

Greek letters
\alpha		\theta
\beta		\iota
\gamma		\kappa
\delta		\lambda
\epsilon		\mu
\zeta		\nu
\eta		\xi

Installation Instructions

You do not need to install anything in the browser to use this extension. The following instructions are for the administrator who installs the extension on the server.

Open configure, and open the "Extensions" section. "Extensions Operation and Maintenance" Tab → "Install, Update or Remove extensions" Tab. Click the "Search for Extensions" button. Enter part of the extension name or description and press search. Select the desired extension(s) and click install. If an extension is already installed, it will not show up in the search results.

You can also install from the shell by running the extension installer as the web server user: (Be sure to run as the webserver user, not as root!)

cd /path/to/foswiki
perl tools/extension_installer <NameOfExtension> install

If you have any problems, or if the extension isn't available in configure, then you can still install manually from the command-line. See https://foswiki.org/Support/ManuallyInstallingExtensions for more help.

Configuration

There are a set of configuration variables that an be set in different places. All of the below variables can be set in your LocalSite.cfg file like this:

$Foswiki::cfg{MathModePlugin}{<Name>} = <value>;

Some of the below variables can only be set this way, some of the may be overridden by defining the respective preference variable.

Name	Preference Variable	Default
HashCodeLength		32
ImagePrefix		'_MathModePlugin_'
Latex2Img		'.../tools/MathModePlugin_latex2img'
LatexBGColor	%LATEXBGCOLOR%	white
LatexFGColor	%LATEXFGCOLOR%	black
LatexFontSize	%LATEXFONTSIZE%	normalsize
ImageType	%LATEXIMAGETYPE%	'png'
LatexPreamble	%LATEXPREAMBLE%	'\usepackage{latexsym}'
ScaleFactor	%LATEXSCALEFACTOR%	1.2
	default background color
	default font size
	default text color
	extension of the image type; possible values are 'gif' and 'png'
	factor to scale images
	latex preamble to include additional packages (e.g. \usepackage{mathptmx} to change the math font) ; note, that the packages amsmath and color are loaded too as they are obligatory
	length of the hash code. If you switch to a different hash function, you will likely have to change this
	string to be prepended to any auto-generated image
	the command to convert a latex formula to an image

Dependencies

Name	Version	Description
dvipng	>0	Required. Required to generate .png output
latex2html	>0	Required. Required by the plugin for all output.

Change History

24 Sep 2025:	added switch to hide server internals in latex error messages (reported by Boud Roukema)
29 Aug 2025:	fixed latex preamble config setting; some minor reorg of code
18 Mar 2014:	make sure the directory is present when caching images
19 Mar 2011:	added Config.spec and DEPENDENCIES to ease installation and configuration; improved compatibility to run this plugin on various Foswiki engines
23 Apr 2009:	converted to foswiki plugin
07 Jan 2009:	certified for foswiki/compat; removed deprecated endRenderingHandler
07 Dec 2007:	replaced templfile with mktemp in the latex2img helper script
13 Nov 2007:	fixed plugin on 4.2
18 Dec 2006:	only use one bgcolor
02 Oct 2006:	don't fail on hierarchical webs; backwards compatible tempfile cleanup
31 Aug 2006:	added NO_PREFS_IN_TOPIC; using xcolor instead of color latex package now to be able to specify colors in html typical codes; default preamble uses latexsym now
07 Aug 2006:	switched from latex2html to latex+dvipng+convert; added size, color, bgcolor to <latex> tag; rendering pngs by default now; reworked plugin settings; added a latex2img shell script; returning full latex error report
04 Aug 2006:	major rewrite; fixed security issues by using the sandbox feature and creating tempfiles properly; added new <latex>...</latex> tag to support multiline formulas; better configurability; better error reporting; fixed issues where images have not been cleaned up regularly; speedup don't clean orphaned images during view but during save; speedup by adding lazy compilation and initialization; implemented a postRenderingHandler for T* V4; prevent auto-generated images stored in pub from being auto-attached using T* V4
03 Apr 2002:	Initial version