CODEWITHSUNDEEP
rggplot2dplyrshiny
Matcha
Matcha

Reputation: 141

radioButtons() input as a condition to filter a data frame in Shiny, doesn't seem to work

Using the midwest dataframe from ggplot2:

# (in app_ui.r)

poverty_sidebar <- sidebarPanel(
  radioButtons(
    inputId = "state",
    label = "State",
    choices = list("IL" = 1, "IN" = 2, "MI" = 3, "OH" = 4, "WI" = 5),
    selected = 1
  ))

poverty_plot <- mainPanel(
  plotOutput(
    outputId = "poverty_plot"
  )
)

# (in app_server.r)

server <- function(input, output) {
  
  output$poverty_plot <- renderPlot({
    
    filtered <- filter(midwest, state == input$state)
    
    plot <- ggplot(data = filtered) +
      geom_col(x = county, y = poppovertyknown)
    
    return(plot)
  })

Doesn't seem to work, gives me a "Object county not found" error. is doing filter(midwest, state == input$state) the wrong approach? Or does the error lie with my radio buttons?

Upvotes: 0

Views: 375

Answers (1)

Croote
Croote

Reputation: 1424

So the code provided is close, you are making two mistakes

  1. choices does not need to map to numeric
  2. x = county, y = poppovertyknown should be in the aes of geom_col so aes(x = county, y = poppovertyknown)

Hence the final working code would be (Note I have added assignment to ui to make it work in single file with call to shinyApp(ui, server)),

library(shiny)
library(dplyr)
library(ggplot2)


poverty_sidebar <- sidebarPanel(
  radioButtons(
    inputId = "state",
    label = "State",
    choices = list("IL", "IN", "MI", "OH", "WI"), # remove mapping to integers
    selected = "IL"
  ))

poverty_plot <- mainPanel(
  plotOutput(
    outputId = "poverty_plot"
  )
)

ui <- 
  fluidPage(
    poverty_sidebar,
    poverty_plot
  )
  

# (in app_server.r)

server <- function(input, output) {
  
  output$poverty_plot <- renderPlot({
    
    filtered <- filter(midwest, state == input$state)
    print(filtered)
    print(input$state)
    filtered0 <<- filtered
    plot <- 
      filtered %>% 
      ggplot() +
      geom_col(aes(x = county, y = poppovertyknown)) # used aes()
    
    return(plot)
  })
  
}

shinyApp(ui, server)

Upvotes: 1

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