<!doctype html>
<html>
  <head>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/d3/4.2.8/d3.min.js" type="text/JavaScript"></script>
    <style>
    </style>
  </head>
  <body>
    <div id="viz">
      <svg style="width:600px;height:600px;" ></svg>
    </div>
    <script>
      var roleScale = d3.scaleOrdinal()
        .range(["#75739F", "#41A368", "#FE9922"]);
      
      var sampleData = d3.range(300).map(() =>
        ({r: 2, value: 200 + d3.randomNormal()() * 50}));
      
      var manyBody = 