add and resize a local image to a .Rmd file in RStudio that will produce a pdf

Question

I am trying to add and resize a local image to a .Rmd file in RStudio that will produce a pdf. I can add the file easily with

![My caption.](path/file.png)

but I have not figured out how to control the size of the image. I tried HTML code with a width attribute, but the image would not appear (I think this only works if outputting to HTML).

<img src="path/file.png" width="200px" />

I could not get this idea to work:

![My caption.](path/file.png =250x)

Is there a way to modify the Rmarkdown script to modify the size of the local image with only RMarkdown and base R?

There is a suggestion to use the png and grid packages, but I am limited to base R for my problem. For other users, however, I think this looks like a good solution.

Answer 1

From @tmpname12345

You can use raw latex to include a figure in pdf_output: \includegraphics[width=250pt]{path/file.png}

Answer 2

You can also specify the size of the image like so:

![](filepath\file.jpg){ width=50% }

The width and height attributes on images are treated specially. When used without a unit, the unit is assumed to be pixels. However, any of the following unit identifiers can be used: px, cm, mm, in, inch and %. There must not be any spaces between the number and the unit.

Source: Pandoc's RMarkdown Documentation - Images

Answer 3

A longer example with latex.

\begin{figure}
\includegraphics[width=250pt]{../images/pricePlot2006_1.5.png}
\caption{Prices through time.}\label{fig:1}
\end{figure}

Other figures created in the .Rmd are numbered automatically.

```{r namedBlock, fig.cap = "Lots of cars."}
plot(mtcars)
```