d3.unconf 2016, v6 by sxywu

index.html

<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <script src="https://d3js.org/d3.v4.min.js"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.15.0/lodash.min.js"></script>
  <script src="https://npmcdn.com/babel-core@5.8.34/browser.min.js"></script>
  <script type="text/javascript" src="//gka.github.io/chroma.js/vendor/chroma-js/chroma.min.js"></script>
  <style>
    body { margin:0;position:fixed;top:0;right:0;bottom:0;left:0; }
    
    svg {
      width: 1000px;
      height: 1000px
    }
  </style>
</head>

<body>
  <svg></svg>
  <script>
// first just make triangle
var midpoint = -2/3;
var halfSide = Math.sqrt(1 / 3);
var favoritesScale = d3.scaleLinear()
	.domain([0, 27])
	.range([midpoint, -1])
var subtri = [
  'M' + (-halfSide) + ',-.99',
  'L0,' + favoritesScale(12),
  'L' + halfSide + ',-.99',
  'Z'
];
var triangle = [
  'M' + (-halfSide) + ',-1',
  'L' + (halfSide) + ',-1',
  'L0,0',
  'Z'
]
    
var svg = d3.select('svg').append('g')
	.attr('transform', 'translate(100, 100)scale(75)');
    
svg.append('path')
	.attr('d', triangle.join(' '));
svg.selectAll('.subtri')
	.data(_.range(3)).enter().append('path')
	.classed('subtri', true)
	.attr('transform', i => 'rotate(' + (i * 120) + ' 0 ' + midpoint + ')')
	.attr('d', subtri.join(' '))
// 	.attr('stroke', '#666')
	.attr('fill', '#fff');
    

  </script>
</body>