treemap.js

var d3 = require('d3'),
    fs = require('fs');

var width = 4000,
    height = 4000;

var bubbles = JSON.parse(fs.readFileSync('bubbles.json'));

var treemap = d3.layout.treemap()
    .size([width, height])
    .sort(function(a, b) {
        return a.value - b.value;
    }).mode('squarify');

var color = d3.scale.category20c();

var data = {
    value:0,
    children: bubbles.map(function(r) {
        return { value: r };
    })
};

var map = treemap.nodes(data);

// fs.writeFileSync('treed', JSON.stringify(tree));

var Canvas = require('canvas'),
    canvas = new Canvas(width, height),
    ctx = canvas.getContext('2d');

ctx.fillStyle = '#fff';
ctx.fillRect(0, 0, width, height);
function position(d, i) {
  if (d.children) return;
  ctx.fillStyle = (d.children) ? '#fff' : color(i);
  ctx.fillRect(~~d.x, ~~d.y,
      ~~Math.max(0, d.dx),
      ~~Math.max(0, d.dy));
}

map.forEach(position);

fs.writeFileSync('tree.png', canvas.toBuffer());