Creating Shiny Apps

A way to build web applications without having to learn/know JavaScript, HTML, etc.

• Instantly updates, outputs change as users modify inputs, without requiring a reload of the browser.
• Build it with R! using “reactive expressions”
• Runs in any R environment( Console R, Rgui for Windows or Mac, ESS, StatET, RStudio, etc.)
• Can be hosted on a server or sign up with shinyapps.io

2 main files required, a few extras to make things fancy:

• ui.R this is the user interface file, which defines how your app will look and serves as the outline for…

• server.R this is the server file which looks for what the user selects (defined in the ui.R) and performs specified operations on the data

• Some extra options:

  • global.R A place to load data, packages, and global components of your app
  • about.R A separate R script that essentially is a custom HTML for a specific “tab” in your app

There are many, but a few that I've found interesting and really well designed:

• Downscaled Climate Data for AK http://spark.rstudio.com/uafsnap/ak_station_cru_eda/
• Dialect Survey Maps http://spark.rstudio.com/jkatz/SurveyMaps/
• A bunch of small examples http://www.mytinyshinys.com/index.html
• US Population Mapping http://glimmer.rstudio.com/jcheng/leaflet-demo/
• Reconstruct Gene Networks http://glimmer.rstudio.com/qbrc/grn/

And plenty more are available…see RStudio's website: (http://www.rstudio.com/shiny/showcase/)

I definitely recommend reading through the RStudio tutorial, it has many useful examples. (http://rstudio.github.io/shiny/tutorial/#)

install.packages("shiny")
library(shiny)

This is an example using data collected at the Center for Watershed Sciences, I build the app because I often get requests for temperature data for a study site. This provides a great way to both visualize, aggregate, and export data.

• River Thermohydrographs http://aquapeek.shinyapps.io/thermohydrographs/

One issue I ran into related to the default app size, but it was easy to adjust using:

runApp(appDir= "PATH/PROJECTS/thermohydrographs")
deployApp() # the app I used was too large for the default container...so...
configureApp("thermohydrographs", size=medium)