R knitr PDF problems with \includegraphics

Question

Using a new empty .rmd document, this code works:

![](RainbowDolphin.png)
\begin{center}
\includegraphics[width=4in]{RainbowDolphin.png}
\end{center}

But without the first line, it doesn't:

\begin{center}
\includegraphics[width=4in]{RainbowDolphin.png}
\end{center}

I get an error:

! Undefined control sequence.
l.71 \includegraphics

pandoc.exe: Error producing PDF from TeX source
Error: pandoc document conversion failed with error 43
In addition: Warning message:
running command '"C:/Program Files/RStudio/bin/pandoc/pandoc" Sampling_03.utf8.md --to latex --from markdown+autolink_bare_uris+ascii_identifiers+tex_math_single_backslash-implicit_figures --output Sampling_03.pdf --template "C:\PROGRA~1\R\R-31~1.2\library\RMARKD~1\rmd\latex\default.tex" --highlight-style tango --latex-engine pdflatex --variable "geometry:margin=1in"' had status 43 
Execution halted

Weird. Any help appreciated!

Answer 1

It's because the latex template doesn't load the graphicx package by default. You can do it manually by adding this to the yaml header:

---
title: "Untitled"
header-includes: \usepackage{graphicx}
output: 
    pdf_document:
        keep_tex: true
---

Answer 2

You may let Pandoc know that you have graphics in this document by specifying the YAML metadata:

---
graphics: yes
---