In jr-packages/jrShiny: R Shiny Exercises

library("jrShiny")
library("shiny")

Exercise 1 (5 minutes)

In RStudio, select File, then New Project. Create a new RStudio project in an empty directory. Call it something useful like shiny_day1_practice.
In Rstudio, select File, then New File, then R markdown....
Select shiny from the options on the left
Give an appropriate title, such as my first app
Once you have created the document, delete line 7 onwards and save the document.
Congrats, you've created your first (albeit empty) shiny app.

Exercise 2 (5 minutes)

Add a code chunk that contains the simple code 1 + 1
Make the chunk display but not run the code, then knit the document
Make the chunk run but not display the code, then knit the document

Exercise 3 (10 minutes)

Add the following widgets to your R markdown document, the options for each widget can be whatever you like at this stage:

selectInput()
sliderInput()
numericInput()
radioButtons(), see ?radioButtons for help

Exercise 4 (10 minutes)

Run the command jrShiny::create_project(). This should create two directories: original and exercises.
Open exercises/chapter1/exercise4.Rmd and run the script.
Display the chosen number on the slider using a renderText()
To simulate random numbers we could use the code runif(n = input$n), display a plot of the random numbers using renderPlot()

Exercise 5 (10 minutes)

iris is an infamous dataset within the programming community. It contains widght and length measurements for the sepal and petal of three different flowers.

Open chapter1/exercise5.Rmd and run.
What is choices = unique(iris$Species) doing?
We can filter the iris data frame for the user's chosen species with the code selected = iris[iris$Species == input$flower_choice,]
- Use renderText() to add text that displays the average petal length for the species chosen by the user.
- (Harder) Display a plot of Petal.Width v Petal.Length for the species chosen by the user.