ioslides_presentation: Convert to an ioslides Presentation

Description

Format for converting from R Markdown to an ioslides presentation.

Usage

ioslides_presentation(logo = NULL,  slide_level = 2, incremental = FALSE, fig_width = 7.5, fig_height = 4.5, fig_retina = 2, fig_caption = TRUE, dev = "png", df_print = "default", smart = TRUE, self_contained = TRUE, widescreen = FALSE, smaller = FALSE, transition = "default", mathjax = "default", analytics = NULL, template = NULL, css = NULL, includes = NULL, keep_md = FALSE, lib_dir = NULL, md_extensions = NULL, pandoc_args = NULL, extra_dependencies = NULL, ...)

Arguments

logo

Path to file that includes a logo for use in the presentation (should be square and at least 128x128)

slide_level

Header level to consider as slide separator (Defaults to header 2)

incremental

TRUE to render slide bullets incrementally. Note that if you want to reverse the default incremental behavior for an individual bullet you can preceded it with >. For example: > - Bullet Text

fig_width

Default width (in inches) for figures

fig_height

Default width (in inches) for figures

fig_retina

Scaling to perform for retina displays (defaults to 2,which currently works for all widely used retina displays). Set toNULL to prevent retina scaling. Note that this will always beNULL when keep_md is specified (this is because fig_retina relies on outputting HTML directly into the markdown document).

fig_caption

TRUE to render figures with captions

dev

Default graphics device to use for figure output

df_print

Method to be used for printing data frames. Valid values include "default", "kable", and "tibble". The "default" method uses print.data.frame. The "kable" method uses the knitr::kable function. The "tibble" method uses the tibble package to print a summary of the data frame. In addition to the named methods you can also pass an arbitrary function to be used for printing data frames.

smart

Produce typographically correct output, converting straight quotes to curly quotes, --- to em-dashes, -- to en-dashes, and ... to ellipses.

self_contained

Produce a standalone HTML file with no external dependencies, using data: URIs to incorporate the contents of linked scripts, stylesheets, images, and videos. Note that even for self contained documents MathJax is still loaded externally (this is necessary because of it's size).

widescreen

Display presentation with wider dimensions.

smaller

Use smaller text on all slides. You can also enable this for individual slides by adding the .smaller attribute to the slide header (see Presentation Size below for details).

transition

Speed of slide transitions. This can be "default", "slower", "faster", or a numeric value with a number of seconds (e.g. 0.5)

mathjax

Include mathjax. The "default" option uses an https URL from the official MathJax CDN. The "local" option uses a local version of MathJax (which is copied into the output directory). You can pass an alternate URL or pass NULL to exclude MathJax entirely.

analytics

A Google analytics property ID

template

Path to a pandoc template to use instead of the default bundled template.

css

One or more css files to include

includes

Named list of additional content to include within the document (typically created using the includes function). If a before_body include is specified then it will replace the standard title slide entirely.

keep_md

Keep the markdown file generated by knitting.

lib_dir

Directory to copy dependent HTML libraries (e.g. jquery, bootstrap, etc.) into. By default this will be the name of the document with _files appended to it.

md_extensions

Markdown extensions to be added or removed from the default definition or R Markdown. See the rmarkdown_format for additional details.

pandoc_args

Additional command line options to pass to pandoc

extra_dependencies, ...

Additional function arguments to pass to the base R Markdown HTML output formatter html_document_base

Value

R Markdown output format to pass to render

Slide Basics

You can create a slide show broken up into sections by using the # and ## heading tags (you can also create a new slide without a header using a horizontal rule (----------). For example here's a simple slide show:

---
title: "Habits"
author: John Doe
date: March 22, 2005
output: ioslides_presentation
--- # In the morning ## Getting up - Turn off alarm
- Get out of bed ## Breakfast - Eat eggs
- Drink coffee # In the evening ## Dinner - Eat spaghetti
- Drink wine ---------- ![picture of spaghetti](images/spaghetti.jpg) ## Going to sleep - Get in bed
- Count sheep

You can add a subtitle to a slide or section by including text after the pipe (|) character. For example:

## Getting up | What I like to do first thing

Display Modes

The following single character keyboard shortcuts enable alternate display modes:

'f' enable fullscreen mode
'w' toggle widescreen mode
'o' enable overview mode
'h' enable code highlight mode
'p' show presenter notes

Pressing Esc exits all of these modes. See the sections below on Code Highlighting and Presenter Mode for additional detail on those modes.

Incremental Bullets

You can render bullets incrementally by adding the incremental option:

---
output:
  ioslides_presentation:
    incremental: true
---

If you want to render bullets incrementally for some slides but not others you can use this syntax:

> - Eat eggs
> - Drink coffee

Presentation Size

You can display the presentation using a wider form factor using the widescreen option. You can specify that smaller text be used with the smaller option. For example:

---
output:
  ioslides_presentation:
    widescreen: true
    smaller: true
---

You can also enable the smaller option on a slide-by-slide basis by adding the .smaller attibute to the slide header:

## Getting up {.smaller}

Adding a Logo

You can add a logo to the presentation using the logo option (the logo should be square and at least 128x128). For example:

---
output:
  ioslides_presentation:
    logo: logo.png
---

A 128x128 version of the logo graphic will be added to the title slide and an icon version of the logo will be included in the bottom-left footer of each slide.

Build Slides

Slides can also have a .build attribute that indicate that their content should be displayed incrementally. For example:

## Getting up {.build}

Slide attributes can be combined if you need to specify more than one, for example:

## Getting up {.smaller .build}

Code Highlighting

It's possible to select subsets of code for additional emphasis by adding a special "highlight" comment around the code. For example:

### 
x <- 10
y <- x * 2
###

The highlighted region will be displayed with a bold font. When you want to help the audience focus exclusively on the highlighted region press the 'h' key and the rest of the code will fade away.

Tables

The ioslides template has an attractive default style for tables so you shouldn't hestiate to add tables for presenting more complex sets of information. Pandoc markdown supports several syntaxes for defining tables which are described in the pandoc online documentation.

Advanced Layout

You can center content on a slide by adding the .flexbox and .vcenter attributes to the slide title. For example:

## Dinner {.flexbox .vcenter}

You can horizontally center content by enclosing it in a div tag with class centered. For example:


This text is centered.

You can do a two-column layout using the columns-2 class. For example:


  ![Image](image.png) - Bullet 1
  - Bullet 2
  - Bullet 3

Note that content will flow accross the columns so if you want to have an image on one side and text on the other you should make sure that the image has sufficient height to force the text to the other side of the slide.

Text Color

You can color content using base color classes red, blue, green, yellow, and gray (or variations of them e.g. red2, red3, blue2, blue3, etc.). For example:


This text is red

Presenter Mode

A separate presenter window can also be opened (ideal for when you are presenting on one screen but have another screen that's private to you). The window stays in sync with the main presentation window and also shows presenter notes and a thumbnail of the next slide. To enable presenter mode add ?presentme=true to the URL of the presentation, for example:

mypresentation.html?presentme=true

The presenter mode window will open and will always re-open with the presentation until it's disabled with:

mypresentation.html?presentme=false

To add presenter notes to a slide you include it within a "notes" div. For example:


This is my *note*. - It can contain markdown
- like this list

Printing and PDF Output

You can print an ioslides presentation from within browsers that have good support for print CSS (i.e. as of this writing Google Chrome has the best support). Printing maintains most of the visual styles of the HTML version of the presentation. To create a PDF version of a presentation you can use Print to PDF from Google Chrome.

Details

See the online documentation for additional details on using the ioslides_presentation format.