# jemdoc: menu{MENU}{latex.html}, showsource
= jemdoc -- latex equations

jemdoc includes support for LaTeX equations. LaTeX source embedded in jemdoc
files is processed by calling [http://www.latex-project.org/ +latex+] and
[http://www.nongnu.org/dvipng/ +dvipng+] (which must both be available for this
feature). Resulting PNG images are then placed on the web page. Equations are
typeset using pure LaTeX.

~~~
jemdoc equation support relies on several pieces, any of which may break. No
guarantees! Support may be limited.
~~~

== Inline equations
The conjugate function $f^\star(y) = \sup_{x \in X}(y^Tx - f(x))$ appears here
inline, and is in the variable $y$. Dollar signs (+\$+) surround the LaTeX
equation in the jemdoc source.

~~~
{Syntax}{}
The sample function $f^\star(y) = \sup_{x \in X}(y^Tx - f(x))$
appears here inline, and is in the variable $y$.
~~~

== Equations on separate lines
To render an equation on its own line, use backslash-escaped round brackets
(+\\(+ and +\\)+). For example, the identity
\(
(I + XY)^{-1} = I - X(I + YX)^{-1}Y
\)
is typeset on its own line. Yes, round brackets instead of square
brackets---this is to avoid a conflict with ordinary square brackets that are
escaped to avoid being a link.  Sorry.

~~~
{Syntax}{}
The identity
\(
    (I \+ XY)^{-1} = I - X(I \+ YX)^{-1}Y
\)
is typeset on its own line.
~~~

Here, the line breaks (and other whitespace) are ignored. As always, the exact
formatting details can be adjusted using CSS.

== Notes
- The baseline is carefully adjusted. The sequences m$m$m and y$y$y (+m\$m\$m+
  and +y\$y\$y+), for example, should be neatly aligned (modulo bad browsers).
- Definition by cases will work as expected, for example, $f(x)$, where
  \(
  f(x) = \left\{
  \begin{array}{ll}
  3, & x \leq 0 \\
  5, & x > 0. \\
  \end{array}\right.
  \)
  (You can view the [latex.jemdoc jemdoc source] for this page.)
- A random inequality might look like $3x + 2y^{4k + 6} \geq z$.
- This page takes about 0.7 seconds to process on an average machine, including
  making all the equations from scratch.
- There are several configuration options for equations. They are detailed on
  the [modelines.html modelines] page.