Cities and Population Map with D3

Based on /curran/752b97cef3f880a813ab

forked from piwodlaiwo's block: World Cities with D3v4

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>D3 Example</title>
    <script src="https://d3js.org/d3.v4.min.js"></script>
    <script src="https://d3js.org/topojson.v2.min.js"></script>
    <script src="d3.tip.js"></script>
    <link href='https://fonts.googleapis.com/css?family=Raleway' rel='stylesheet' type='text/css'>
    <style>

body { margin:0;position:fixed;top:0;right:0;bottom:0;left:0; background:black;}
    svg { width:100%; height: 100% }
    path {fill:none;color:#fff;}
    .graticule {
      fill: none;
      stroke: #bbb;
      stroke-width: .5px;
      stroke-opacity: .5;
    }

circle {
        stroke: red;
        fill: rgba(0,0, 0, 0.2);
      }

circle:hover { 
        stroke-width: 2px;
      }

.d3-tip {
        font-family: 'Raleway', sans-serif;
        font-size: 1.5em;
        line-height: 1;
        padding: 7px;
        background: black;
        color: lightgray;
        border-radius: 20px;
      }
    </style>
  </head>
  <body>
    <script>
      
      var xColumn = "longitude";
      var yColumn = "latitude";
      var rColumn = "population";
      var peoplePerPixel = 50000;
      
var width = 960,
    height = 580;

var projection = d3.geoMercator();

var path = d3.geoPath().projection(projection);
  
var graticule = d3.geoGraticule();

var svg = d3.select("body").append("svg")
    .attr("width", width)
    .attr("height", height);
  
svg.append("defs").append("path")
    .datum({type: "Sphere"})
    .attr("id", "sphere")
    .attr("d", path);

svg.append("use")
    .attr("class", "stroke")
    .attr("xlink:href", "#sphere");

svg.append("use")
    .attr("class", "fill")
    .attr("xlink:href", "#sphere");

svg.append("path")
    .datum(graticule)
    .attr("class", "graticule")
    .attr("d", path);
  
d3.json("https://gist.githubusercontent.com/mbostock/4090846/raw/d534aba169207548a8a3d670c9c2cc719ff05c47/world-50m.json", function(error, world) {
  if (error) throw error;

var countries = topojson.feature(world, world.objects.countries).features,
      neighbors = topojson.neighbors(world.objects.countries.geometries);

svg.selectAll(".country")
      .data(countries)
    .enter().insert("path", ".graticule")
      .attr("class", "country")
      .attr("d", path)
			.style("fill", "#fff");
      
      
      
      
      var populationFormat = d3.format(",");

var tip = d3.tip()
        .attr("class", "d3-tip")
        .offset([-10, 0])
        .html(function(d) {
          return d.name + ": " + populationFormat(d.population);
        });

svg.call(tip);

var rScale = d3.scaleSqrt();

function render(data){

rScale.domain([0, d3.max(data, function (d){ return d[rColumn]; })]);

// Compute the size of the biggest circle as a function of peoplePerPixel.
        var peopleMax = rScale.domain()[1];
        var rMin = 0;
        var rMax = Math.sqrt(peopleMax / (peoplePerPixel * Math.PI));
        rScale.range([rMin, rMax]);
        
        var circles = svg.selectAll("circle").data(data);
      circles.enter().append("svg:circle")
          .attr("cx", function (d){ return projection([d[xColumn],d[yColumn]])[0]; })
          .attr("cy", function (d){ return projection([d[xColumn],d[yColumn]])[1]; })      
          .attr("r",  function (d){ return rScale(d[rColumn]); })
          .on("mouseover", tip.show)
          .on("mouseout", tip.hide);      
        circles.exit().remove();
        
        
      }

function type(d){
        d.latitude = +d.latitude;
        d.longitude = +d.longitude;
        d.population = +d.population;
        return d;
      }

d3.csv("geonames_cities100000.csv", type, render);

});

d3.select(self.frameElement).style("height", height + "px");

</script>
  </body>

https://d3js.org/d3.v4.min.js

https://d3js.org/topojson.v2.min.js