Introduction to Shiny

Building Web Applications with Shiny in R

Ramnath Vaidyanathan

VP of Product Research

Introduction to Shiny

Shiny web app of wait times for Old Faithful geyser to explode, with number of histogram bins interactively adjustable

What is a web app?

Updates based on user input/interaction
Made up of UI & server

What is a web app?

NY Times "Paths to the White House" web app gif

Displays paths to the White House for different presidential candidates.

What is a web app?

DataCamp mobile app

A gif of the DataCamp mobile app, displaying an example of a practice question.

How does a web app work?

A web app is a thing that updates based on user input/interaction Diagram showing how clients and servers are connected to power web apps on the internet

What is Shiny?

What is shiny diagram, displaying how server code and the UI interface are separate but work together to create an app

Why should data scientists build web apps?

Iris dataset clustered by sepal.length and sepal.width, creating 3 distinct clusters

Why should data scientists build web apps?

plot_kmeans(
  data = iris, 
  x = 'Sepal.Length', 
  y = 'Sepal.Width', 
  nb_clusters = 3
)

Iris dataset clustered by sepal.length and sepal.width, creating 3 distinct clusters

Why should data scientists build web apps?

library(shiny)
ui <- fluidPage(
  h1('K-Means Clustering App'),
  selectInput('x', 'Select x', names(iris), 'Sepal.Length'),
  selectInput('y', 'Select y', names(iris), 'Sepal.Width'),
  numericInput('nb_clusters', 'Select number of clusters', 3),
  plotly::plotlyOutput('kmeans_plot')
)

server <- function(input, output, session){
  output$kmeans_plot <- plotly::renderPlotly({
    plot_kmeans(iris, input$x, input$y, input$nb_clusters)
  })
}

shinyApp(ui = ui, server = server)

Why should data scientists build web apps?

web app that does K-means clustering of Iris dataset

Let's practice!

Building Web Applications with Shiny in R