garrettgman · December 22, 2015 11:19 · Sep 6, 2013 · Sep 6, 2013 · Sep 6, 2013 · Sep 6, 2013
diff --git a/server.R b/server.R
@@ -1,6 +1,6 @@
 library(shiny)
-require(maps)
-require(mapproj)
+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")
 

diff --git a/server.R b/server.R
@@ -1,5 +1,6 @@
 library(shiny)
-library(maps)
+require(maps)
+require(mapproj)
 
 counties <- readRDS("counties.RDS")
 

diff --git a/server.R b/server.R
@@ -1,7 +1,7 @@
 library(shiny)
 library(maps)
 
-counties <- readRDS("data/counties.RDS")
+counties <- readRDS("counties.RDS")
 
 mp <- map("county", plot=FALSE, namesonly=TRUE)
 c.order <- match(mp, 

diff --git a/counties.RDS b/counties.RDS
diff --git a/server.R b/server.R
@@ -0,0 +1,57 @@
+library(shiny)
+library(maps)
+
+counties <- readRDS("data/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)
+    })
+})
diff --git a/ui.R b/ui.R
@@ -0,0 +1,24 @@
+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")
+  )
+))