# $\LaTeX$ Syntax

The following section describes how to add equations written using $\LaTeX$ to your documentation.

## Escaping Characters in Docstrings

Since some characters used in $\LaTeX$ syntax, such as $ and \, are treated differently in docstrings. They need to be escaped using a \ character as in the following example: """ Here's some inline maths: \\sqrt[n]{1 + x + x^2 + \\ldots}. Here's an equation: \\frac{n!}{k!(n - k)!} = \\binom{n}{k} This is the binomial coefficient. """ func(x) = # ... Note that for equations on the manual pages (in .md files) the escaping is not necessary. So, when moving equations between the manual and docstrings, the escaping \ characters have to the appropriately added or removed. To avoid needing to escape the special characters in docstrings the raw"" string macro can be used, combined with @doc: @doc raw""" Here's some inline maths: \sqrt[n]{1 + x + x^2 + \ldots}. Here's an equation: \frac{n!}{k!(n - k)!} = \binom{n}{k} This is the binomial coefficient. """ func(x) = # ... A related issue is how to add dollar signs to a docstring. They need to be double-escaped as follows: """ The cost was \\\$1.
"""

## Inline Equations

Here's some inline maths: \sqrt[n]{1 + x + x^2 + \ldots}.

which will be displayed as

Here's some inline maths: $\sqrt[n]{1 + x + x^2 + \ldots}$.

## Display Equations

Here's an equation:

math
\frac{n!}{k!(n - k)!} = \binom{n}{k}


This is the binomial coefficient.

---

To write a system of equations, use the aligned environment:

math
\begin{aligned}
\nabla\cdot\mathbf{E}  &= 4 \pi \rho \\
\nabla\cdot\mathbf{B}  &= 0 \\
\nabla\times\mathbf{E} &= - \frac{1}{c} \frac{\partial\mathbf{B}}{\partial t} \\
\nabla\times\mathbf{B} &= - \frac{1}{c} \left(4 \pi \mathbf{J} + \frac{\partial\mathbf{E}}{\partial t} \right)
\end{aligned}


These are Maxwell's equations.


which will be displayed as

Here's an equation:

$$$\frac{n!}{k!(n - k)!} = \binom{n}{k}$$$

This is the binomial coefficient.

To write a system of equations, use the aligned environment:

\begin{aligned} \nabla\cdot\mathbf{E} &= 4 \pi \rho \\ \nabla\cdot\mathbf{B} &= 0 \\ \nabla\times\mathbf{E} &= - \frac{1}{c} \frac{\partial\mathbf{B}}{\partial t} \\ \nabla\times\mathbf{B} &= - \frac{1}{c} \left(4 \pi \mathbf{J} + \frac{\partial\mathbf{E}}{\partial t} \right) \end{aligned}

These are Maxwell's equations.