How to insert plain picture (jpeg / png) from chunk with knitr

Question

I want to insert a picture at the beginning of text using a code block, not markdown. I am using the Tufte handout template output: rmarkdown::tufte_handout and when I insert it straight after the YAML header but before TOC like this:

\centering
![width='100%'](./cropped-banner_efpt.jpg)
\raggedright
\tableofcontents
\clearpage

the image then spans the main body. I know that with chunks there is an option to have the chunk to span the whole page placing fig.fullwidth = TRUE in the chunk header, but I am a bit stuck with this as I am not generating any graph from data and I do not know how to simpy place an image from within a chunk.

Another matter was that when I set toc: true in the YAML header, the image would only come after the inserted toc - that is why I am inserting toc with the latex command.

Thank you for your suggestions.

Solution

When a figure is not generated from R code, you may use knitr::include_graphics() to insert it to the document, e.g.

```{r echo=FALSE, out.width='100%'}
knitr::include_graphics('./cropped-banner_efpt.jpg')
```

Comments

[r0berts]

Thank you, this works very well. In tufte-handout template it goes to full width of the page only if you give option fig.fullwidth=TRUE in the header. But out.width='100%' option is also very useful to know. I too found another solution but that is with inserting latex code such as: \begin{figure*} \includegraphics{././cropped-banner_efpt.jpg} \end{figure*} In any case thanks a bunch and knitr is phenomenal!

[Pablo Adames]

Works really well on R version 3.6.3 (2020-02-29) for x86_64-pc-linux-gnu (64-bit). Thanks!

[dsz]

While considerably more verbose than ![...](...), this method give access to far more control in terms of placement and size, and can therefore be useful even for static images.