This plugin allows you to include mathematics in a TWiki page, 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>
Make sure they are installed and check the paths to the programs latex, dvipng and convert in the latex2img shiped with this plugin
Edit the file <path-to-twiki>/pub/TWiki/MathModePlugin/latex2img accordingly
Visit configure in your TWiki installation, and enable the plugin in the {Plugins} section.
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:
$TWiki::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 prefrence variable.
length of the hash code. If you switch to a different hash function, you will likely have to change this
ImagePrefix
'_MathModePlugin_'
string to be prepended to any auto-generated image
ImageType
%LATEXIMAGETYPE%
'png'
extension of the image type; possible values are 'gif' and 'png'
Latex2Img
'.../TWiki/MathModePlugin/latex2img'
the script to convert a latex formula to an image
LatexPreamble
%LATEXPREAMBLE%
'\usepackage{latexsym}'
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
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 TWiki's 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 TWiki V4; prevent auto-generated images stored in pub from being auto-attached using TWiki V4