D3 Examples - immigration-svg

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<!DOCTYPE html>
<meta charset="utf-8">
<div class='main-viz'>
<h1>Immigration</h1>
<canvas width="960" height="760"></canvas>
</div>
<script src="https://d3js.org/d3.v4.min.js"></script>
<script>
​
var canvas = document.querySelector("canvas"),
    context = canvas.getContext("2d"),
    width = canvas.width,
    height = canvas.height,
    tau = 2 * Math.PI;
​
var nodes = d3.range(1000).map(function(i) {
  return {
    r: 3,
    index: i,
    color: i < 10 ? "brown" : "#dddddd"  };
});
​
var simulation = d3.forceSimulation(nodes)
    .velocityDecay(0.2)
    .force("x", d3.forceX().strength(0.001))
    .force("y", d3.forceY().strength(0.1))
    .force("brown", isolate(d3.forceX(width/8), function(d) { return d.color === 'brown'; }))
    .force("#dddddd", isolate(d3.forceX(-width/8), function(d) { return d.color === '#dddddd'; }))
    .force("collide", d3.forceCollide().radius(function(d) { return d.r + 5; }).iterations(5))
    .on("tick", ticked);
​
function ticked(d) {
  context.clearRect(0, 0, width, height);
  context.save();
  context.translate(width / 2, height / 2);
​
  nodes.forEach(drawNode);
  context.restore();
}
  
  function drawNode(d) {
  context.beginPath();
  context.moveTo(d.x + d.r, d.y);
  context.arc(d.x, d.y, d.r, 0, tau);
  context.fillStyle = d.color;
  context.fill();
}
  
  function isolate(force, filter) {
    console.log(force,filter);
  var initialize = force.initialize;
  force.initialize = function() { initialize.call(force,        nodes.filter(filter)); };
  return force;
}
​
</script>
    