In R markdown in RStudio, how can I prevent the source code from running off a pdf page?

Question

I currently have some code that looks like so:

```{r, tidy=TRUE} plot(DT$age, DT$height, xlab = "Age of participant in Trials", ylab = "Height of participant in       Trials") ``` 

Now, it was my understanding that setting tidy to TRUE would make it so that when I knit the code together, the code would not go running off the page and would wrap by itself. However, I sporadically still get run off source code displays when I do commands like the one above. Is there another function that would guarantee the wrapping of code? Thanks!

Answer 1

Use the width.cutoff argument inside tidy.opts knitr options to specify the output width :

```{r, tidy=TRUE, tidy.opts=list(width.cutoff=60)} plot(DT$age, DT$height, xlab = "Age of participant in Trials", ylab = "Height of participant in trials") ``` 

You can define this option globally for your whole file with a chunk like this :

```{r} library(knitr) opts_chunk$set(tidy.opts=list(width.cutoff=60),tidy=TRUE) ``` 

The tidy.opts options are passed to the formatR package which does the tidying (if I understand correctly). In-depth informations about formatR can be found here :

http://yihui.name/formatR/