two-column layouts in RStudio presentations/slidify/pandoc

Question

I'm trying to come up with a good system for generating slides and accompanying handouts. The ideal system would have the following properties:

• beautiful in both presentation (PDF/HTML) and handout (PDF) layouts (handouts should have room for taking notes)
• embedded R chunks, figures, other JPG/PNG pictures, etc.
• easy to compose
• build using command-line tools
• bibliography support
• pandoc slide separator format (automatically generate a new slide after headers of a specified level) is preferred
• I can live with a little bit of additional processing (e.g. via sed), but would prefer not to write a huge infrastructure
• two-column layouts: there is a SO post on how to get multi-column slides from pandoc, but it is LaTeX- rather than HTML-oriented.
• ability to adjust sizes of embedded images (other than R-generated figures) and column widths on the fly

Here's what I've discovered so far about the various options:

• Slidify:
  • doesn't do pandoc slide separator format, although there is a workaround
  • the suggestion for creating handouts is to print to PDF; I'd like to leave room for notes etc. (I could probably figure out a way to do that using something like PDFtk or psnup ...)
• RStudio presentations (.Rpres files):
  • does lots of things nicely, including multi-columns with specified widths
  • doesn't support pandoc slide separator format
  • I can't figure out what's going on under the hood. There is RStudio documentation that describes the translation process for regular HTML, but it doesn't seem to cover the R presentation format (which isn't quite the same). (I have previously invested some effort in figuring out how to get RStudio-like output via pandoc ...), which means I can't generate slides etc. from the command line.
• RStudio's Development Version (as of March 2014) comes bundled with Pandoc and version 2 of rmarkdown. It addresses many of the above issues with the .Rpres format.
• pandoc: may be the only markdown-translator that has features such as footnotes, bibliography support, etc.. I can also use pandoc to generate LaTeX using the tufte-handout class, which meets my criteria of beauty.
  • Unfortunately, it seems not to have built-in two-column format support. Yihui Xie's HTML5 example doesn't show any two-column examples, and it claims (on slide 5) that clicking the "Knit HTML" button in RStudio is equivalent to pandoc -s -S -i -t dzslides --mathjax knitr-slides.md -o knitr-slides.html, but it doesn't seem to be ...
• LaTeX/beamer: I could simply compose in Rnw (knitr-dialect Sweave) rather than R markdown to begin with. This would give me ultimate flexibility ...
  • despite many years of LaTeX use I do find LaTeX composition more of a pain than markdown composition.

After all that, my specific question is: what's the best (easiest) way to generate a two-column layout for HTML output?

Any other advice will also be appreciated.

Answer 1

This is an old Q, but I was recently plagued by a similar question, here's what I found:

Using the RPres format, two columns can be specified like so (details). Note that RPres can only be converted to HTML by clicking a button in RStudio, there doesn't seem to be any command line method, which is a bit annoying. Despite, that I'd say it is currently the simplest and most flexible method for getting slide columns with markdown:

===   Two Column Layout   ===  This slide has two columns  ***  ```{r, echo=FALSE} plot(cars) ``` 

Some flexibility is afforded by adjusting the column proportions:

===  Two Column Layout   === left: 30% This slide has two columns  ***  ```{r, echo=FALSE} plot(cars) ``` 

With rmarkdown we can get two columns, but with no control over where the break is, which is a bit of a problem:

--- output: ioslides_presentation ---   ## Two Column Layout  {.columns-2}  This slide has two columns   ```{r, echo=FALSE} plot(cars) ``` 

We can also mix markdown and LaTeX in an Rmd file using the beamer_presentation format in RStudio to get two columns like this, but can't run any code in either column, which is a limitation:

--- output: beamer_presentation ---  Two Column Layout  -------  \begin{columns} \begin{column}{0.48\textwidth} This slide has two columns \end{column} \begin{column}{0.48\textwidth} If I put any code in here I get an error, see https://support.rstudio.com/hc/communities/public/questions/202717656-Can-we-have-columns-in-rmarkdown-beamer-presentations- \end{column} \end{columns} 

Seems like a regular Rnw LaTeX doc is the best way to get columns if you want to use LaTex, not this markdown hybrid (cf. two column beamer/sweave slide with grid graphic)

In all of the above an image can be placed in an column.

The slidify website has instructions on making two columns here: http://slidify.org/customize.html but it's not clear what has to go into the assets/layouts folder to make it work

Answer 2

You can use fenced_divs notation or ::: to create columns or `Two Content layout'. See also this page to know more about the notation.

## Slide With Image Left  ::: columns  :::: column left ::::  :::: column right  ```{r your-chunk-name, echo=FALSE, fig.cap="your-caption-name"} knitr::include_graphics("your/figure/path/to/the-image.pdf")  #The figure will appear on the right side of the slide... ``` ::::  ::: 

Since pandoc 2+, which supports the notation, was implemented in RStudio v1.2+, you may need to install RStudio v1.2+ first. The installation is easy enough (at least in my case); just download and install RStudio v1.2+. In the way of installation, the former version of RStudio on your computer will be replaced with the new one without uninstalling it manually.

The ::: notation can be used even when you knit .Rmd files with beamer_presentation option, as well as when you create HTML slides. So we don't have to neither mix markdown and LaTeX notation in one file, nor add additional codes any longer: just knit the file as you knit other .Rmd with other options.