Shiny App not drawing labels on scale_fill_gradient

[EricLi0480]

Hello everyone,

Here is a section of code that I have:

mydata <- read.csv("data/svi2020.csv")
countypop$pop_2015[2044:2131] <- mydata$"AREA_SQMI"

plot_usmap(data = countypop, values = "pop_2015", include = c("OH"), color = "black") + 
  scale_fill_gradient(low = "white", high = "black", 
                      name = "chosen_column") + 
  theme(legend.position = "right") +
  labs(title = paste("input$datasetname", " [", sep = ""))

Here is that same code, in a Shiny App's server.R:

output$testmap <- renderPlot({
    mydata <- read.csv("data/svi2020.csv")
    countypop$pop_2015[2044:2131] <- mydata$"AREA_SQMI"
    
    plot_usmap(data = countypop, values = "pop_2015", include = c("OH"), color = "black") + 
      scale_fill_gradient(low = "white", high = "black", 
                          name = "chosen_column") + 
      theme(legend.position = "right") +
      labs(title = paste("input$datasetname", " [", sep = ""))
  })

The first outputs the following to the plot window (see attachment)

However, in the Shiny App, the labels (700,600,...) on the scale are not shown. Why might this be happening? Thanks!

[nirgrahamuk]

There is no principled reason why this would happen; it doesnt happen for the most trivial example of placing a plot_usmap in a shiny app

library(usmap)
library(shiny)

ui <- fluidPage(
  plotOutput("myplot")
)

server <- function(input, output, session) {
  output$myplot <- renderPlot({
    plot_usmap(data = statepop, values = "pop_2015")
    
  })
}

shinyApp(ui, server)

Perhaps you can provide a reproducible example for the forum to work with ?

How do I share data for a reprex?

You might use tools such as the library datapasta, or the base function dput() to share a portion of data in code form, i.e. that can be copied from forum and pasted to R session.

Reprex Guide

[EricLi0480]

server.R:

server <- function(input, output, session) {
  
  output$datasetcolumn2 <- renderUI({
    chosen_dataset <- read.csv(paste("data/", input$datasetname, sep = ""))
    selectInput("datasetcolumn", "Data choice:",
                # Only allow user to plot numerical data
                Filter(function(x) class(chosen_dataset[,match(x, names(chosen_dataset))])=="numeric",
                       names(chosen_dataset))
    )
  })
  
  output$map <- renderPlot({
    chosen_dataset <- read.csv(paste("data/", input$datasetname, sep = ""))
    
    chosen_column <- input$datasetcolumn
    chosen_index <- match(chosen_column, names(chosen_dataset))
    
    # Replace data in countypop with desired data
    # Indices of Ohio county data are from 2044 to 2131
    # FIPS codes of Ohio counties: 39001 to 39175 (odds)
    try( 
      countypop$pop_2015[2044:2131] <- chosen_dataset[,chosen_index],
      silent = TRUE # Suppress temporary error message that appears
    )
    
    plot_usmap(data = countypop, values = "pop_2015", include = c("OH"), color = "black") +
      scale_fill_gradient(low = "white", high = "black",
                          name = chosen_column) +
      theme(legend.position = "right") +
      labs(title = paste(input$datasetname, " [", chosen_column, "]", sep = ""))
    
  })
  
  # For testing
  output$testmap <- renderPlot({
    mydata <- read.csv("data/svi2020.csv")
    countypop$pop_2015[2044:2131] <- mydata$"AREA_SQMI"
    
    plot_usmap(data = countypop, values = "pop_2015", include = c("OH"), color = "black") + 
      scale_fill_gradient(low = "white", high = "black", 
                          name = "chosen_column") + 
      theme(legend.position = "right") +
      labs(title = paste("input$datasetname", " [", sep = ""))
  })
  # End testing
}

ui.R:

ui <- fluidPage(
  title = "Ohio Datasets",
  titlePanel("Visualizing Ohio Datasets"),
  sidebarPanel(
    selectInput("datasetname", "Select dataset:",
                list.files(paste(getwd(), "/data", sep = "")) # List of datasets
                )
  ),
  mainPanel(
    uiOutput("datasetcolumn2"), # Dropdown to select data to plot from dataset
    plotOutput("map"),
    plotOutput("testmap") # For debugging, temporary
  )
)

app.R:

library(shiny)
library(usmap)
library(ggplot2)

source("ohio-ui.R")
source("ohio-server.R")

shinyApp(ui = ui, server = server) # Run app

Here's a link to my data folder: Download - UploadNow.io

[EricLi0480]

Hi! I just tried running your code on my computer, and it doesn't work either (it doesn't show the labels like in your screenshot).

[nirgrahamuk]

My example was from

 packageVersion("usmap")
[1] ‘0.7.0’

But I expect even older versions would have supported showing legends, so unsure how to help you.

Are you perhaps in an environment that retains its state from session to session ? that could cause errors to propogate, so explicitly going to a clean R session might help in such a case.

[EricLi0480]

I have the same version of the package. I also tried simply running the command plot_usmap(data = statepop, values = "pop_2015") in the console, and the correct plot (with labels on the gradient) appeared in the plots panel. It just doesn't show up with your Shiny example, and I just cannot understand why. I'm running shiny, version 1.7.5.

[nirgrahamuk]

non-reproducible issues are the hardest category to solve...
Perhaps upgrade to shiny 1.8.0; maybe something will be kicked loose