D3 Dorling cartogram with rectangular states by davo

index.html

<!DOCTYPE html>
<html>
  <head>
    <meta http-equiv="Content-Type" content="text/html;charset=utf-8">
    <title>Dorling Cartogram</title>
    <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.1.10/d3.js"></script>
    <style>
    #chart {
      width: 960px;
      height: 470px;
    }

    circle {
      stroke: #000;
      stroke-width: .5px;
    }
    </style>
  </head>
  <body>
    <div id="chart"></div>
    <button id="restart" onclick="force.start()">Reheat</button>
    <button id="update" onclick="update()">Renew</button>

    <script>
    window.onload = function() {
      var force = d3.layout.force()
          .charge(0)
          .gravity(0)
          .size([960, 470]);

      var update;

      d3.json("us-state-centroids.json", function(states) {
        var project = d3.geo.albersUsa(),
            idToNode = {},
            links = [];

        update = function() {
          d3.select("svg").remove();

          var svg = d3.select("#chart").append("svg")
              .attr("width", 960)
              .attr("height", 470)
            .append("g")
              .attr("transform", "translate(50,20)");

          var nodes = states.features.map(function(d) {
            var xy = project(d.geometry.coordinates);
            return idToNode[d.id] = {
              x: xy[0],
              y: xy[1],
              gravity: {x: xy[0], y: xy[1]},
              width: Math.random()*100+25,
              height: Math.random()*100+25
            };
          });

          var overlapColor = d3.scale.linear()
            .domain([0, 7])
            .range(["#2070a0", "orange"]);

          force
              .nodes(nodes)
              .links(links)
              .start()
              .on("tick", function(e) {
            var k = e.alpha,
                kg = k * .02,
                spaceAround = 0.;

            nodes.forEach(function(a, i) {
              a.x += (a.gravity.x - a.x) * kg;
              a.y += (a.gravity.y - a.y) * kg;

              a.overlapCount = 0;

              nodes.slice(i + 1).forEach(function(b) {
                dx =  (a.x - b.x);
                dy =  (a.y - b.y);

                adx = Math.abs(dx);
                ady = Math.abs(dy);

                mdx = (1+spaceAround)* (a.width + b.width)/2;
                mdy = (1+spaceAround)* (a.height + b.height)/2;

                if (adx < mdx  &&  ady < mdy) {          
                  l = Math.sqrt(dx * dx + dy * dy);

                  lx = (adx - mdx) / l * k;
                  ly = (ady - mdy) / l * k;

                  if (lx > ly  &&  ly > 0) lx = 0;
                  else if (ly > lx  &&  lx > 0) ly = 0;

                  dx *= lx;
                  dy *= ly;
                  a.x -= dx;
                  a.y -= dy;
                  b.x += dx;
                  b.y += dy;

                  a.overlapCount++;
                }
              });
            });

            svg.selectAll("rect")
                .style("fill", function(d) { return overlapColor(d.overlapCount); })
                .attr("x", function(d) { return d.x - d.width/2; })
                .attr("y", function(d) { return d.y - d.height/2; });

            svg.selectAll("line")
              .attr("x2", function(d) { return d.x; })
              .attr("y2", function(d) { return d.y; });

            svg.selectAll("circle.end")
              .attr("cx", function(d) { return d.x; })
              .attr("cy", function(d) { return d.y; });
          });

          var g = svg.selectAll("g")
              .data(nodes)
            .enter()
              .append("g")
                .attr("transform", "translate(100,100),scale(0.5)");

          g.append("circle")
            .attr("stroke", "#000")
            .attr("fill", "#fff")
            .attr("cx", function(d) { return d.gravity.x; })
            .attr("cy", function(d) { return d.gravity.y; })
            .attr("r", 3);

          g.append("line")
            .attr("stroke", "#000")
            .attr("opacity", "0.3")
            .attr("x1", function(d) { return d.gravity.x; })
            .attr("y1", function(d) { return d.gravity.y; });

          g.append("rect")
            .attr("opacity", 0.75)
            .attr("x", function(d) { return d.x - d.width/2; })
            .attr("y", function(d) { return d.y - d.height/2; })
            .attr("width", function(d, i) { return d.width; })
            .attr("height", function(d, i) { return d.height; });

          g.append("circle")
            .attr("class", "end")
            .attr("stroke", "#000")
            .attr("fill", "#fff")
            .attr("r", 3);
        };

        update();
      });
    };
    </script>

  </body>
</html>

us-state-centroids.json

{"type":"FeatureCollection","features":[
{"type":"Feature","id":"01","geometry":{"type":"Point","coordinates":[-86.766233,33.001471]},"properties":{"name":"Alabama","population":4447100}},
{"type":"Feature","id":"02","geometry":{"type":"Point","coordinates":[-148.716968,61.288254]},"properties":{"name":"Alaska","population":626932}},
{"type":"Feature","id":"04","geometry":{"type":"Point","coordinates":[-111.828711,33.373506]},"properties":{"name":"Arizona","population":5130632}},
{"type":"Feature","id":"05","geometry":{"type":"Point","coordinates":[-92.576816,35.080251]},"properties":{"name":"Arkansas","population":2673400}},
{"type":"Feature","id":"06","geometry":{"type":"Point","coordinates":[-119.355165,35.458606]},"properties":{"name":"California","population":33871648}},
{"type":"Feature","id":"08","geometry":{"type":"Point","coordinates":[-105.203628,39.500656]},"properties":{"name":"Colorado","population":4301261}},
{"type":"Feature","id":"09","geometry":{"type":"Point","coordinates":[-72.874365,41.494852]},"properties":{"name":"Connecticut","population":3405565}},
{"type":"Feature","id":"10","geometry":{"type":"Point","coordinates":[-75.561908,39.397164]},"properties":{"name":"Delaware","population":783600}},
{"type":"Feature","id":"11","geometry":{"type":"Point","coordinates":[-77.014001,38.910092]},"properties":{"name":"District of Columbia","population":572059}},
{"type":"Feature","id":"12","geometry":{"type":"Point","coordinates":[-81.634622,27.795850]},"properties":{"name":"Florida","population":15982378}},
{"type":"Feature","id":"13","geometry":{"type":"Point","coordinates":[-83.868887,33.332208]},"properties":{"name":"Georgia","population":8186453}},
{"type":"Feature","id":"15","geometry":{"type":"Point","coordinates":[-157.524452,21.146768]},"properties":{"name":"Hawaii","population":1211537}},
{"type":"Feature","id":"16","geometry":{"type":"Point","coordinates":[-115.133222,44.242605]},"properties":{"name":"Idaho","population":1293953}},
{"type":"Feature","id":"17","geometry":{"type":"Point","coordinates":[-88.380238,41.278216]},"properties":{"name":"Illinois","population":12419293}},
{"type":"Feature","id":"18","geometry":{"type":"Point","coordinates":[-86.261515,40.163935]},"properties":{"name":"Indiana","population":6080485}},
{"type":"Feature","id":"19","geometry":{"type":"Point","coordinates":[-93.049161,41.960392]},"properties":{"name":"Iowa","population":2926324}},
{"type":"Feature","id":"20","geometry":{"type":"Point","coordinates":[-96.536052,38.454303]},"properties":{"name":"Kansas","population":2688418}},
{"type":"Feature","id":"21","geometry":{"type":"Point","coordinates":[-85.241819,37.808159]},"properties":{"name":"Kentucky","population":4041769}},
{"type":"Feature","id":"22","geometry":{"type":"Point","coordinates":[-91.457133,30.699270]},"properties":{"name":"Louisiana","population":4468976}},
{"type":"Feature","id":"23","geometry":{"type":"Point","coordinates":[-69.719931,44.313614]},"properties":{"name":"Maine","population":1274923}},
{"type":"Feature","id":"24","geometry":{"type":"Point","coordinates":[-76.797396,39.145653]},"properties":{"name":"Maryland","population":5296486}},
{"type":"Feature","id":"25","geometry":{"type":"Point","coordinates":[-71.363628,42.271831]},"properties":{"name":"Massachusetts","population":6349097}},
{"type":"Feature","id":"26","geometry":{"type":"Point","coordinates":[-84.170753,42.866412]},"properties":{"name":"Michigan","population":9938444}},
{"type":"Feature","id":"27","geometry":{"type":"Point","coordinates":[-93.583003,45.210782]},"properties":{"name":"Minnesota","population":4919479}},
{"type":"Feature","id":"28","geometry":{"type":"Point","coordinates":[-89.593164,32.566420]},"properties":{"name":"Mississippi","population":2844658}},
{"type":"Feature","id":"29","geometry":{"type":"Point","coordinates":[-92.153770,38.437715]},"properties":{"name":"Missouri","population":5595211}},
{"type":"Feature","id":"30","geometry":{"type":"Point","coordinates":[-111.209708,46.813302]},"properties":{"name":"Montana","population":902195}},
{"type":"Feature","id":"31","geometry":{"type":"Point","coordinates":[-97.403875,41.183753]},"properties":{"name":"Nebraska","population":1711263}},
{"type":"Feature","id":"32","geometry":{"type":"Point","coordinates":[-116.304648,37.165965]},"properties":{"name":"Nevada","population":1998257}},
{"type":"Feature","id":"33","geometry":{"type":"Point","coordinates":[-71.463342,43.153046]},"properties":{"name":"New Hampshire","population":1235786}},
{"type":"Feature","id":"34","geometry":{"type":"Point","coordinates":[-74.428055,40.438458]},"properties":{"name":"New Jersey","population":8414350}},
{"type":"Feature","id":"35","geometry":{"type":"Point","coordinates":[-106.342108,34.623012]},"properties":{"name":"New Mexico","population":1819046}},
{"type":"Feature","id":"36","geometry":{"type":"Point","coordinates":[-74.645228,41.507548]},"properties":{"name":"New York","population":18976457}},
{"type":"Feature","id":"37","geometry":{"type":"Point","coordinates":[-79.667654,35.553334]},"properties":{"name":"North Carolina","population":8049313}},
{"type":"Feature","id":"38","geometry":{"type":"Point","coordinates":[-99.334736,47.375168]},"properties":{"name":"North Dakota","population":642200}},
{"type":"Feature","id":"39","geometry":{"type":"Point","coordinates":[-82.749366,40.480854]},"properties":{"name":"Ohio","population":11353140}},
{"type":"Feature","id":"40","geometry":{"type":"Point","coordinates":[-96.834653,35.597940]},"properties":{"name":"Oklahoma","population":3450654}},
{"type":"Feature","id":"41","geometry":{"type":"Point","coordinates":[-122.579524,44.732273]},"properties":{"name":"Oregon","population":3421399}},
{"type":"Feature","id":"42","geometry":{"type":"Point","coordinates":[-77.075925,40.463528]},"properties":{"name":"Pennsylvania","population":12281054}},
{"type":"Feature","id":"44","geometry":{"type":"Point","coordinates":[-71.448902,41.753318]},"properties":{"name":"Rhode Island","population":1048319}},
{"type":"Feature","id":"45","geometry":{"type":"Point","coordinates":[-81.032387,34.034551]},"properties":{"name":"South Carolina","population":4012012}},
{"type":"Feature","id":"46","geometry":{"type":"Point","coordinates":[-99.043799,44.047502]},"properties":{"name":"South Dakota","population":754844}},
{"type":"Feature","id":"47","geometry":{"type":"Point","coordinates":[-86.397772,35.795862]},"properties":{"name":"Tennessee","population":5689283}},
{"type":"Feature","id":"48","geometry":{"type":"Point","coordinates":[-97.388631,30.943149]},"properties":{"name":"Texas","population":20851820}},
{"type":"Feature","id":"49","geometry":{"type":"Point","coordinates":[-111.900160,40.438987]},"properties":{"name":"Utah","population":2233169}},
{"type":"Feature","id":"50","geometry":{"type":"Point","coordinates":[-72.814309,44.081127]},"properties":{"name":"Vermont","population":608827}},
{"type":"Feature","id":"51","geometry":{"type":"Point","coordinates":[-77.835857,37.750345]},"properties":{"name":"Virginia","population":7078515}},
{"type":"Feature","id":"53","geometry":{"type":"Point","coordinates":[-121.624501,47.341728]},"properties":{"name":"Washington","population":5894121}},
{"type":"Feature","id":"54","geometry":{"type":"Point","coordinates":[-80.820221,38.767195]},"properties":{"name":"West Virginia","population":1808344}},
{"type":"Feature","id":"55","geometry":{"type":"Point","coordinates":[-89.001006,43.728544]},"properties":{"name":"Wisconsin","population":5363675}},
{"type":"Feature","id":"56","geometry":{"type":"Point","coordinates":[-107.008835,42.675762]},"properties":{"name":"Wyoming","population":493782}},
{"type":"Feature","id":"72","geometry":{"type":"Point","coordinates":[-66.58765,18.19958]},"properties":{"code":"PR","name":"Puerto Rico","population":3808610}}
]}