A shiny app that helps you map demographic variables from the 2010 US Census

counties.RDS

server.R

library(shiny)
if(!require(maps)) stop("This app requires the maps package.\nPlease install it and then try again.")
if(!require(mapproj)) stop("This app requires the maps package.\nPlease install it and then try again.")

counties <- readRDS("counties.RDS")

mp <- map("county", plot=FALSE, namesonly=TRUE)
c.order <- match(mp, 
  paste(counties$region, counties$subregion, sep = ","))

shinyServer(function(input, output) {
  
  indexInput <- reactive({
    var <- switch(input$var, 
      "Total Population (logged)" = log(counties$pop),
      "Percent White" = counties$white,
      "Percent Black" = counties$black,
      "Percent Hispanic" = counties$hispanic,
      "Percent Asian" = counties$asian)
    
    var <- pmax(var, input$range[1])
    var <- pmin(var, input$range[2])
    as.integer(cut(var, 100, include.lowest = TRUE, 
                   ordered = TRUE))[c.order]
  })
  
  shadesInput <- reactive({
    switch(input$var, 
      "Percent White" = colorRampPalette(c("white", "darkgreen"))(100),
      "Percent Black" = colorRampPalette(c("white", "black"))(100),
      "Percent Hispanic" = colorRampPalette(c("white", "darkorange3"))(100),
      "Percent Asian" = colorRampPalette(c("white", "darkviolet"))(100))
  })
  
  legendText <- reactive({  
    inc <- diff(range(input$range)) / 4
    c(paste0(input$range[1], " % or less"),
      paste0(input$range[1] + inc, " %"),
      paste0(input$range[1] + 2 * inc, " %"),
      paste0(input$range[1] + 3 * inc, " %"),
      paste0(input$range[2], " % or more"))
  })
        
  
  output$mapPlot <- renderPlot({
    fills <- shadesInput()[indexInput()]
    
    map("county", fill = TRUE, col = fills, 
        resolution = 0, lty = 0, projection="polyconic", 
        myborder = 0, mar = c(0,0,0,0))
    map("state",col = "white", fill=FALSE, add=TRUE, lty=1, 
        lwd=1,projection="polyconic", myborder = 0, 
        mar = c(0,0,0,0))
    legend("bottomleft", legend = legendText(), 
           fill = shadesInput()[c(1, 25, 50, 75, 100)], 
           title = input$var)
    })
})

ui.R

library(shiny)

shinyUI(pageWithSidebar(
  
  headerPanel("censusVis"),
  
  sidebarPanel(
    helpText("Create demographic maps with information from the 2010 US Census."),
    selectInput("var", "Choose a variable to display",
                choices = c(
                            "Percent White",
                            "Percent Black",
                            "Percent Hispanic",
                            "Percent Asian"
                            ),
                selected = "Percent White"
    ),
    sliderInput("range", "Range of interest:",
                min = 0, max = 100, value = c(0, 100))
  ),
  mainPanel(
    plotOutput("mapPlot", height = "600px")
  )
))

thanks for the code, i noticed you used 'county' as dataset is it included in R, is it possible to apply this code for countries other than the US?