# R Language Including LaTeX Preample Commands

## Example

There are two possible ways of including LaTeX preamble commands (e.g. `\usepackage`) in a RMarkdown document.

1. Using the YAML option `header-includes`:

``````---
title: "Including LaTeX Preample Commands in RMarkdown"
- \renewcommand{\familydefault}{cmss}
- \usepackage[cm, slantedGreek]{sfmath}
- \usepackage[T1]{fontenc}
output: pdf_document
---

```{r setup, include=FALSE}
knitr::opts_chunk\$set(echo = TRUE, external=T)
```

# Section 1

As you can see, this text uses the Computer Moden Font!
``````

2. Including External Commands with `includes`, `in_header`

``````---
title: "Including LaTeX Preample Commands in RMarkdown"
output:
pdf_document:
includes:
---

```{r setup, include=FALSE}
knitr::opts_chunk\$set(echo = TRUE, external=T)
```

# Section 1

As you can see, this text uses the Computer Modern Font!
``````

Here, the content of includes.tex are the same three commands we included with `header-includes`.

Writing a whole new template

A possible third option is to write your own LaTex template and include it with `template`. But this covers a lot more of the structure than only the preamble.

``````---
title: "My Template"
author: "Martin Schmelzer"
output:
pdf_document:
template: myTemplate.tex
---
``````