Incremental Sub-Bullets in RMarkdown and Beamer

Introduction

As a professional in the field of technical writing, I have come across several challenges while working with RMarkdown and Beamer presentations. One such challenge is the creation of incremental sub-bullets on slides. In this article, we will delve into the problem, explore the existing solutions, and discuss how to implement incremental sub-bullets using the latest version of pandoc.

Understanding Pandoc

Before we dive into the solution, let’s take a brief look at pandoc, the software that powers RMarkdown and Beamer presentations. Pandoc is a powerful document processor that can convert documents from one format to another. In the context of RMarkdown and Beamer, pandoc acts as a bridge between the R language and the LaTeX formatting system used by Beamer.

The Problem with Incremental Sub-Bullets

When working with sub-bullets in RMarkdown and Beamer, we often encounter issues with incremental behavior. This occurs when pandoc fails to properly nest sub-bullets or when it treats sub-bullets as plain text. The existing solutions to this problem involve inserting a specific number of spaces before the sub-bullet lines, but these approaches have limitations.

In the Stack Overflow post that inspired this article, the author shares their experiences with incremental sub-bullets in RMarkdown and Beamer. They provide an example of an RMarkdown file containing failed attempts at implementing incremental sub-bullets. We will build upon this example to explore a more effective solution.

The Solution: Updating Pandoc

As indicated by the Stack Overflow post, updating pandoc is the key to resolving the issue with incremental sub-bullets. The latest version of pandoc (2.1.3) includes significant improvements for handling nested lists and sub-bullets.

To update pandoc on a Mac using Homebrew, follow these steps:

Install Homebrew by running /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)" in the Terminal.
Update Homebrew to the latest version by running brew update.
Install pandoc using brew install pandoc.

Once the installation is complete, you can verify that pandoc has been updated successfully by checking its version.

Compiling RMarkdown with Incremental Sub-Bullets

After updating pandoc, we can compile our RMarkdown file again to test the incremental sub-bullet behavior. To do this, follow these steps:

Open your RMarkdown file in a text editor.
Insert the following code into the first slide:

>- Bullet 1 >- Bullet 2

This nests, but does not increment

Bullet 1
Bullet 2
- subbullet 1
- subbullet 2

3.  Compile the RMarkdown file using `rmarkdown::render("your_file.Rmd", engine = "beamer")` in R.

If pandoc has been updated successfully, you should see that the sub-bullets are properly nested and incremented.

Using Markdown Syntax to Control Incremental Behavior
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In addition to updating pandoc, we can also use Markdown syntax to control incremental behavior. When using inline HTML syntax (`&gt;+`), pandoc treats it as plain text rather than a sub-bullet. To avoid this issue, you can replace `&gt;+` with the corresponding Markdown character `+`.

Here is an updated version of the RMarkdown file that uses Markdown syntax to control incremental behavior:
```markdown
&gt;- Bullet 1
&gt;- Bullet 2

## This nests and increments correctly

- Bullet 1
- Bullet 2
    + subbullet 1
    + subbullet 2

## This treats the inline HTML as plain text

&gt;+ subbullet 1
&gt;+ subbullet 2

Conclusion

Incremental sub-bullets can be a challenging feature to implement in RMarkdown and Beamer presentations. However, by updating pandoc to its latest version (2.1.3), we can resolve the issue with incremental sub-bullets. This approach involves compiling our RMarkdown files again using rmarkdown::render() in R.

In addition to updating pandoc, using Markdown syntax correctly can help control incremental behavior. By avoiding inline HTML syntax (>+) and instead using the corresponding Markdown character +, we can ensure that sub-bullets are properly nested and incremented.

Conclusion

In this article, we explored the challenge of implementing incremental sub-bullets in RMarkdown and Beamer presentations. We discussed how updating pandoc to its latest version (2.1.3) resolves the issue with incremental sub-bullets. Additionally, we touched on using Markdown syntax correctly to control incremental behavior.

By following the steps outlined in this article, you should be able to implement incremental sub-bullets effectively in your RMarkdown and Beamer presentations.

Last modified on 2024-02-13