Looking further: Building interactive web apps in R + Shiny

Lecture 26

Dr. Mine Çetinkaya-Rundel

Duke University
STA 199 - Fall 2024

December 5, 2024

Warm-up

Announcements

Course and TA evaluations due Monday, 12/9
- TA of the Year award nominations: Email dus@sta.duke.edu.
Project due at 5 pm today
Peer evaluations due at 5 pm tomorrow

Interactive web apps in R with Shiny

Shiny

Shiny is an R package that makes it easy to build interactive web apps straight from R. You can host standalone apps on a webpage or embed them in R Markdown documents or build dashboards. You can also extend your Shiny apps with CSS themes, htmlwidgets, and JavaScript actions.

Shiny App

Server

⇄

Client / Browser

+ +

Anatomy of an App

library(shiny)

shinyApp(
  ui = list(
    # new (to you) widgets go here
  ),
  
  server = function(input, output, session) {
    # somewhat familiat (to you) code goes here
  }
)

Shiny Widgets Gallery

https://shiny.posit.co/r/gallery/widgets/widget-gallery/

Live demo

ae-21-weather-forecast

Go to your ae project in RStudio.
If you haven’t yet done so, make sure all of your changes up to this point are committed and pushed, i.e., there’s nothing left in your Git pane.
If you haven’t yet done so, click Pull to get today’s application exercise file: ae-21-weather-forecast.R.
Work through the application exercise in class, and render, commit, and push your edits.

Data

Scaffold 1

Find variables that are numeric and not constant for selected city

Scaffold 2

Calculate number of days that mention “Rain”, “Snow”, “Clear” in conditions