How to adjust code block line spacing in knitr?

Question

When you use knitr to render r-markdown files into either HTML or pdf, the code chunks in the output document have what to me looks like excessive line spacing. When I want to output the results of summary() this turns what is normally a concise output into something way too long.

Here's a comparison:

I've looked and looked and I cannot find a way to adjust knitr's line spacing.

Of course I could use xtable to format the summary() output, but it only wants to output the "tabular" part of the output and doesn't include the R^2 etc. in it.

Is there a way to adjust knitr's line spacing so it is more compact?

Answer 1

You can do this for HTML output. Create your own style.css file in the same directory as your document, and decrease the line spacing there:

div pre {
  line-height: normal;
}

Then reference that CSS file in your YAML front matter:

---
...
output:
  html_document:
    css: style.css
---

I'm not sure how to do it for PDF. Note that most LaTeX commands in your document will be passed directly through pandoc to the layout engine, so if you can find a solution using raw LaTeX it may be possible to inject it directly into your R Markdown document.