Width of R code chunk output in RMarkdown files knitr-ed to html

Question

Question:

What is the current working solution to set the width of r code output in html files? I would like to set width to something big and use a slider in the html output.

options(width = XXX) seems not to work anymore.

Example:

---
title: "Width test"
output:
  html_document:
    theme: default
---
```{r global_options, echo = FALSE, include = FALSE}
options(width = 999)
knitr::opts_chunk$set(echo = FALSE, warning = FALSE, message = FALSE,
                      cache = FALSE, tidy = FALSE, size = "small")
```
```{r}
sessionInfo()
```
```{r}
dataM <- matrix(rnorm(100, 5, 2), ncol = 15)
dataM
```

Result:

sessionInfo() output on the screenshot above.

Related:

(options(width = 999) is not working for me)

knitr: How to prevent text wrapping in output?

How to adjust the output width of RStudio Markdown output (to HTML)

Answer 1

You can use this to make the pre blocks scroll horizontally if it overflows.

---
title: "Width test"
output:
  html_document:
    theme: default
---

<style>
pre {
  overflow-x: auto;
}
pre code {
  word-wrap: normal;
  white-space: pre;
}
</style>

```{r global_options, echo = FALSE, include = FALSE}
options(width = 999)
knitr::opts_chunk$set(echo = FALSE, warning = FALSE, message = FALSE,
                      cache = FALSE, tidy = FALSE, size = "small")
```
```{r}
sessionInfo()
```
```{r}
dataM <- matrix(rnorm(100, 5, 2), ncol = 20)
dataM
```

---

For a scrollable height, create a container div with a max height and a overflow-y: auto; or overflow-y: scroll;

Similar question/answer

---
title: "Height test"
output:
  html_document:
    theme: default
---

<style>
.pre-scrolly {
  max-height: 150px;
  overflow-y: auto;
}
</style>

<div class='pre-scrolly'>
```{r}
sessionInfo()
```
</div>