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Pseudo-Demers Cartogram
Raw
.block
license: gpl-3.0
Raw
README.md

This is not a true Demers cartogram; it lacks links between adjacent features. Instead of trying to preserve connectedness, this pseudo-cartogram tries to preserve locality, putting each square as close as possible to its origin without overlapping.

Raw
index.html
<!DOCTYPE html>
<meta charset="utf-8">
<title>Demers Cartogram</title>
<style>
rect {
fill: #eee;
stroke: #000;
stroke-width: 1.5px;
}
</style>
<svg width="960" height="500"></svg>
<script src="https://d3js.org/d3.v4.min.js"></script>
<script>
// Ratio of Obese (BMI >= 30) in U.S. Adults, CDC 2008
var valueById = [
NaN, 0.187, 0.198, NaN, 0.133, 0.175, 0.151, NaN, 0.100, 0.125,
0.171, NaN, 0.172, 0.133, NaN, 0.108, 0.142, 0.167, 0.201, 0.175,
0.159, 0.169, 0.177, 0.141, 0.163, 0.117, 0.182, 0.153, 0.195, 0.189,
0.134, 0.163, 0.133, 0.151, 0.145, 0.130, 0.139, 0.169, 0.164, 0.175,
0.135, 0.152, 0.169, NaN, 0.132, 0.167, 0.139, 0.184, 0.159, 0.140,
0.146, 0.157, NaN, 0.139, 0.183, 0.160, 0.143
];
var svg = d3.select("svg"),
margin = {top: 0, right: 0, bottom: 0, left: 0},
width = svg.attr("width") - margin.left - margin.right,
height = svg.attr("height") - margin.top - margin.bottom,
padding = 3;
var projection = d3.geoAlbersUsa();
var radius = d3.scaleSqrt()
.domain([0, d3.max(valueById)])
.range([0, 30]);
d3.json("us-state-centroids.json", function(error, states) {
if (error) throw error;
var nodes = states.features
.filter(function(d) { return !isNaN(valueById[+d.id]); })
.map(function(d) {
var point = projection(d.geometry.coordinates),
value = valueById[+d.id];
if (isNaN(value)) fail();
return {
x: point[0], y: point[1],
x0: point[0], y0: point[1],
r: radius(value),
value: value
};
});
var simulation = d3.forceSimulation()
.force("x", d3.forceX(function(d) { return d.x0; }))
.force("y", d3.forceY(function(d) { return d.y0; }))
.force("collide", collide)
.nodes(nodes)
.on("tick", tick);
var node = svg.selectAll("rect")
.data(nodes)
.enter().append("rect")
.attr("width", function(d) { return d.r * 2; })
.attr("height", function(d) { return d.r * 2; });
function tick(e) {
node.attr("x", function(d) { return d.x - d.r; })
.attr("y", function(d) { return d.y - d.r; });
}
function collide() {
for (var k = 0, iterations = 4, strength = 0.5; k < iterations; ++k) {
for (var i = 0, n = nodes.length; i < n; ++i) {
for (var a = nodes[i], j = i + 1; j < n; ++j) {
var b = nodes[j],
x = a.x + a.vx - b.x - b.vx,
y = a.y + a.vy - b.y - b.vy,
lx = Math.abs(x),
ly = Math.abs(y),
r = a.r + b.r + padding;
if (lx < r && ly < r) {
if (lx > ly) {
lx = (lx - r) * (x < 0 ? -strength : strength);
a.vx -= lx, b.vx += lx;
} else {
ly = (ly - r) * (y < 0 ? -strength : strength);
a.vy -= ly, b.vy += ly;
}
}
}
}
}
}
});
</script>
Display the source blob
Display the rendered blob
Raw
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}}
]}
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