Moving pictures: Interactive documents with R and Markdown

Goals for this talk

• Share my experience creating a tool for visualizing household travel survey data (htsViewer)
• Demonstrate some tools for presenting data
  • internally for quality assurance, communication to colleagues
  • externally for reporting to clients
• Focus is on interactive data presentation

htsViewer

• Goal is to make it easy to see HTS data
• Project is at https://github.com/RSGInc/htsViewer
• Show (running locally)

Outline

• R + Markdown = RMarkdown
• leaflet
• DT (DataTable)
• flexdashboard
• crosstalk
• Shiny

R + Markdown = RMarkdown

R

• If you work with data, you probably already know a lot about R
• if you don't, it's one of the main computer languages we use here at RSG
• Extremely versatile language for data analysis
• One of the most widely used data languages in the world, along with SQL and Python
• Based heavily on S, a statistical computer language developed at Bell Labs in the 1970's
• Excellent data visualization facilities built-in

Markdown

## Markdown

This is **Markdown**, a lightweight markup language. You use it to format text.

I like it because:

  - It is very readable even in plain text
  - code is easy to distinguish: `foo`, `bar`, `baz`.
  - It's versatile!  Use in  [Teams](https://support.microsoft.com/en-ie/office/use-markdown-formatting-in-teams-4d10bd65-55e2-4b2d-a1f3-2bebdcd2c772) and [Github](https://guides.github.com/features/mastering-markdown/), not to mention [RStudio](https://rmarkdown.rstudio.com/).
  - Create HTML pages, presentations, Word docs, PDF, dashboards, etc.
  - Learn more at [markdownguide.org](https://www.markdownguide.org/getting-started/) and try it out at [dillinger.io](https://dillinger.io/).

Markdown

This is Markdown, a lightweight markup language. You use it to format text.

I like it because:

• It is very readable even in plain text
• code is easy to distinguish: foo, bar, baz.
• It's versatile! Use in Teams and Github, not to mention RStudio.
• Create HTML pages, presentations, Word docs, PDF, dashboards, etc.
• Learn more at markdownguide.org and try it out at dillinger.io.

RMarkdown

• Combines plain text of Markdown with R code
• Compiling replaces R code with output of R - figures, tables, text
• Can export to HTML, PDF, Word, presentations (like this one), dashboards
• Can produce interactive documents with htmlwidgets or shiny (or both combined)
• Easy to share as a stand-alone HTML file
• Results can use RSG branding (CSS is helpful)
• Show [example](https://github.com/landisrm/rTED_2020/blob/main/01_rmarkdown_static.Rmd

Interactive Documents

htmlwidgets

• htmlwidgets: packages that wrap JavaScript libraries and make them accessible in R
• DT (DataTables)
• leaflet (Leaflet)
• Show example
• File is shareable as a single .html file.

flexdashboard

• https://rmarkdown.rstudio.com/flexdashboard/
• "Easy interactive dashboards for R"
• Based on RMarkdown
• Provides easy to use layouts
• Incorporates htmlwidgets and/or Shiny
• Show example

crosstalk

• https://rstudio.github.io/crosstalk/
• Interactivity between widgets through shared data object
• Very simple to set up
• All client side. No server. (easy to share as a file)
• Limitations
  • Dataset has to be relatively small (fits in file)
  • Not all graphics are supported (e.g. histograms, lines on maps)
  • Not many packages can interact with crosstalk
    • DT
    • Leaflet
    • Plotly
• Show example

Shiny

• https://shiny.rstudio.com/
• R package for building interactive web apps
• Much more flexible than RMarkdown alone but harder to set up
• RStudio has ability to run locally (e.g. htsViewer)
• Sharing requires a web server
• We (RSG) have an account on shinyapps.io

shinyapps.io

shinyapps.io

• Excellent for sharing Rmarkdown and Shiny web apps
• Share a link instead of a file
• Easier to debug and modify than a set of scripts sent to client
• Custom URLs, e.g. demo.rsginc.com/rted_2020/shiny_test/
• Secure
  • Can manage access to individuals
  • Can access databases so data isn't stored in web page

Summary

Packages

• rmarkdown
• leaflet
• datatable
• flexdashboard
• crosstalk
• shiny
• shinyapps.io

Links

• Code and HTML files for this presentation: https://github.com/landisrm/rTED_2020
• Flexdashboard document: https://rsginc.shinyapps.io/landis_demo_05_shiny_flex_crosstalk/
• Shinydashboard document: https://rsginc.shinyapps.io/landis_demo_06_shiny_filter_map_from_table/
• shinyapps.io: https://www.shinyapps.io/admin/#/dashboard