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}


        

Answer 1

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

---
graphics: yes
---

Answer 2

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
---