How to create a R shiny app with a drop down menu to choose between plots-CodePudding

I'm trying to create a shiny app which chooses bar plots from the drop down menu and displays it.

I have two plots which are:

The first one is a total death per continent plot assigned to variable :continent_death_total_plot

The second one is a total infection per continent plot assigned to variable: continent_infection_total_plot

My code:

server <- function(input,output,session){
 
    output$plot <- renderPlot({
      if (input$choices == "Total Death Per continent"){
        continental_death_total_plot
      }else{
        continental_infection_total_plot
      }
      
      
  })
}
  
  
ui <- fluidPage(
  h1("R shiny Bar Plot"),
  selectInput(inputId = "covid_plot",
              label = "Choose category",
              choices = c("Total Death Per Continent","Total Infections Per Continent")),
  plotOutput("plot")
)


shinyApp(ui = ui, server = server)

When I run this code I get an error:

argument is of length zero

CodePudding user response：

One thing you have to do is change if (input$choices == "Total Death Per continent") to if (input$covid_plot == "Total Death Per continent"), as your selectInput- widget is called covid_plot .

In your example continental_death_total_plot and continental_infection_total_plot are not defined here, but I assume this is because you wanted to keep the example short.

CodePudding user response：

Here is an example using shinyjs() and hide and show:

library(shiny)
library(shinyjs)

ui <- fluidPage(
  useShinyjs(),
  h1("R shiny Bar Plot"),
  selectInput(inputId = "covid_plot",
              label = "Choose category",
              choices = c("Total Death Per Continent","Total Infections Per Continent")),
  hidden(plotOutput("continental_death_total_plot")),
  hidden(plotOutput("continental_infection_total_plot"))
)

server <- function(input,output,session){
  
  output$continental_death_total_plot <- renderPlot({
    plot(mtcars)
  })
  
  output$continental_infection_total_plot <- renderPlot({
    plot(iris$Sepal.Length)
  })
  
  
  observeEvent(input$covid_plot,{
    if (input$covid_plot == "Total Death Per Continent"){
      hide('continental_infection_total_plot')
      show('continental_death_total_plot')
    }else{
      hide('continental_death_total_plot')
      show('continental_infection_total_plot')
    }
  })

}

shinyApp(ui = ui, server = server)