R Shiny Reactive Histogram wrong Input?

Question

I have a Shiny app that's doing with a server and ui function like this:

df<- read_csv(path_here)

ui <- fluidPage(
  
  # App title ----
  titlePanel("Histograms!"),
  
  # Sidebar layout with input and output definitions ----
  sidebarLayout(
    
    # Sidebar panel for inputs ----
    sidebarPanel(
      
      checkboxGroupInput("Company", 
                         "Company", 
                         choices = unique(df$Company)
                         ),
      checkboxGroupInput("predicted_condition", 
                         "Predicted Condition", 
                         choices = unique(df$Predicted.Condition)
      )
      ),
    
    # Main panel for displaying outputs ----
    mainPanel(
      
      # Output: Histogram ----
      plotOutput(outputId = "distPlot")
      
    )
  )
)  
server<- function( input, output, session){
  reactive_data <- reactive({
    df %>% 
      filter(Company %in% input$Company)%>%
      filter(Predicted.Condition %in% input$Predicted_Condition)%>%
      select(Predicted.Probability)
  })
  
  output$distPlot <- renderPlot({
    hist(reactive_data())
  })
}

Basically I'm making a histogram where the user can use check boxes called Company and Predicted_Condition. Their selections would filter the corresponding columns in my df, then I'd make a histogram of the probabilities left in the Predicted.Probability column.

However, when I run this I get an error that says x must be numeric even though I've checked that the Predicted.Probability column is numeric. Any suggestions on what to do here?

Perhaps you can share some sample data with dput() to help you. — YBS
select always returns a dataframe, use pull to get a vector. Without seeing example data, it's hard to tell where the breaks error comes from — starja
I ran dput on my Predicted.Probability column. The last few entries were: 0.000703995, 0.000594523, 0.000214589, 0.000145538, 0.00028317, 0.000564918, 0.000354667, 0.000280292, 0.000117386, 0.000207468, 0.000323793, 0.011153646) Running summary on the column yields a min of 0.0001 and a max of 1.0000, but I'm still getting invalid number of breaks error — lvnwrth

Peter D Peter D · Accepted Answer · 2020-10-22T00:49:09

It's hard to know without your data and your ui, but it seems like you are trying to make a histogram from a dataframe. Yes, your column may contain numeric values, but you are essentially filtering down to a dataframe with one column, not a numeric vector. Try this:

server<- function( input, output, session){
  reactive_data <- reactive({
    filtered_dat <- df %>% 
      filter(Company %in% input$Company)%>%
      filter(Predicted.Condition %in% input$Predicted_Condition)

    return(filtered_dat$Predicted.Probability))
  })
  
  output$distPlot <- renderPlot({
    hist(reactive_data())
  })
}

R Shiny Reactive Histogram wrong Input?

1 Answers