Shiny中的动态过滤器和无功图

Question

Issues between inputs and plot output

Hi,

I'm testing out a basic ShinyApp where I can generate a plot of commercial services broken down by geography and service type.

The idea is I want the user to use three drop-down menu inputs, each dependent upon the previous selection, to subset the data, which then gets output in a ggplot.

However, I'm having issues connecting the inputs to the plot output (see below). The inputs are working fine and reactive when selected, but I can't work out how to link that to the plot, I get the feeling I'm not using the right data source (but have no idea how to ensure it is). Furthermore, I'm not familiar with how I would go about adding a third filter (for "service") seeing as I don't know how to link my data source in the first place.

Sorry this is probably simple, but some help would be really appreciated.

UI

 #Data
 Test <- dataframe(
           Geography1 = c("Region","Local Authority","County"...),
           Geography2 = c("North West","Aldershot","Cheshire"...),
           Service = c("Shop","Cafe","Library"...),
           Overall_rating = c("Awesome","Good","Fantatstic"...),
           Locations = c(4000, 1300, 1700...)
  )

 #SHINY APP
 ui <- fluidPage(
  titlePanel("Tool"),
   sidebarLayout(
    sidebarPanel(
     uiOutput("geography1"),
     uiOutput("geography2"),
     uiOutput("service")),

  mainPanel(
     plotOutput("plot", height = "400px"))
     )
  )

Server

   server <- function(input, output) {

 output$geography1 = renderUI({
    selectInput(inputId = "geog1",
              label = "Geography 1:", 
              choices = as.character(unique(Test$Geography1)),
              selected = "Region")
  })

 output$geography2 = renderUI({

   datasub <- Test[Test$Geography1 == input$geog1, "Name"]

     selectInput(inputId = "geog2", 
                 label = "Geography2:", 
                 choices = unique(datasub),
                 selected = unique(datasub)[1])
  })

  output$service = renderUI({

     datasub2 <- unique(datasub)

     selectInput(inputId = "service",
                 label = "Service type:",
                 choices = unique(...),
                 selected = unique(...)[1])
   })

  output$plot = renderPlot({

    ggplot(datasub2(),aes(x = Overall_rating, y = Locations, fill= Overall_rating))+
     geom_bar(stat = "identity")

   })
 }

  shinyApp(ui, server)

Answer 1

It's hard to tell how the provided data is supposed to be filtered in the app but this code will at least run and be interactive. Hopefully from there you can figure out how to adjust the dataset.

As BigDataScientist said one fault is that you're not using a reactive dataset.

#Data
Test <- data.frame(
  Geography1 = c("Region","Local Authority","County"),
  Geography2 = c("North West","Aldershot","Cheshire"),
  Service = c("Shop","Cafe","Library"),
  Overall_rating = c("Awesome","Good","Fantatstic"),
  Locations = c(4000, 1300, 1700)
)

#SHINY APP
ui <- fluidPage(
  titlePanel("Tool"),
  sidebarLayout(
    sidebarPanel(
      uiOutput("geography1"),
      uiOutput("geography2"),
      uiOutput("service")),

    mainPanel(
      plotOutput("plot", height = "400px"))
  )
)

server <- function(input, output) {

  output$geography1 = renderUI({
    selectInput(inputId = "geog1",
                label = "Geography 1:", 
                choices = as.character(unique(Test$Geography1)),
                selected = "Region")
  })

  datasub <- reactive({
    Test[Test$Geography1 == input$geog1,]
  })

  output$geography2 = renderUI({
    selectInput(inputId = "geog2", 
                label = "Geography2:", 
                choices = unique(datasub()[,"Geography2"]),
                selected = unique(datasub()[,"Geography2"])[1])
  })

  datasub2 <- reactive({
    datasub()[Test$Geography2 == input$geog2, ]
  })

  output$service = renderUI({
    selectInput(inputId = "service",
                label = "Service type:",
                choices = unique(datasub2()[,"Service"]),
                selected = unique(datasub2()[,"Service"])[1])
  })

  datasub3 <- reactive({
    datasub()[Test$Service == input$service, ]
  })

  output$plot = renderPlot({
    ggplot(datasub3(),aes(x = Overall_rating, y = Locations, fill= Overall_rating))+
      geom_bar(stat = "identity")

  })
}


shinyApp(ui, server)