Bilevel graph of 28 sites and their trackers

<!DOCTYPE html>
<meta charset="utf-8">
<style>

circle,
path {
  cursor: pointer;
}

circle {
  fill: none;
  pointer-events: all;
}

</style>
<body>
<script src="https://d3js.org/d3.v3.min.js"></script>
<script>

var colors = {

"haosou.com":"#CD2626",
"xiaomi.com":"#CD2626",
"bing.com":"#5687d1",
"weibo.com":"#CD2626",
"uber.com":"#5687d1",
"xunlei.com":"#CD2626",
"instagram.com":"#5687d1",
"baidu.com":"#CD2626",
"sohu.com":"#CD2626",
"youku.com":"#CD2626",
"taobao.com":"#CD2626",
"meituan.com":"#CD2626",
"qq.com":"#CD2626",
"163.com":"#CD2626",
"twitter.com":"#5687d1",
"apple.com":"#5687d1",
"sina.com.cn":"#CD2626",
"toutiao.com":"#CD2626",
"google.com":"#5687d1",
"hao123.com":"#CD2626",
"wandoujia.com":"#CD2626",
"amazon.com":"#5687d1",
"renren.com":"#CD2626",
"alipay.com":"#CD2626",
"10086.cn":"#CD2626",
"tmall.com":"#CD2626",
"yahoo.com":"#5687d1",
"facebook.com":"#5687d1",

"RU":"#6E8B3D",
"FR":"#bbbbbb",
"CN":"#CD2626",
"CA":"#FFFF00",
"DE":"#de783b",
"JP":"#7b615c",
"US":"#5687d1",
"HK":"#B23AEE",
"GB":"#E0FFFF",
"Others":"#030303"
};

var margin = {top: 350, right: 480, bottom: 350, left: 480},
    radius = Math.min(margin.top, margin.right, margin.bottom, margin.left) - 10;

var hue = d3.scale.category10();

var luminance = d3.scale.sqrt()
    .domain([0, 1e6])
    .clamp(true)
    .range([90, 20]);

var svg_ = d3.select("body").append("svg")
    .attr("width", margin.left + margin.right)
    .attr("height", margin.top + margin.bottom);
    var svg =svg_
  .append("g")
    .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

var partition = d3.layout.partition()
    .sort(function(a, b) { return d3.ascending(a.name, b.name); })
    .size([2 * Math.PI, radius]);

d3.json("flare-top28.json", function(error, root) {
  if (error) throw error;
  //drawLegend();
  //addLegend();

// Compute the initial layout on the entire tree to sum sizes.
  // Also compute the full name and fill color for each node,
  // and stash the children so they can be restored as we descend.
  partition
      .value(function(d) { return d.size; })
      .nodes(root)
      .forEach(function(d) {
        d._children = d.children;
        d.sum = d.value;
        d.key = key(d);
        d.fill = fill(d);
      });

// Now redefine the value function to use the previously-computed sum.
  partition
      .children(function(d, depth) { return depth < 2 ? d._children : null; })
      .value(function(d) { return d.sum; });

var center = svg.append("circle")
      .attr("r", radius / 3)
      .on("click", zoomOut);

center.append("title")
      .text("zoom out");

.text(function (d) {
        console.log(d);
        return d.depth == 1 ? d.name : "";
    })

function zoomIn(p) {
    if (p.depth > 1) p = p.parent;
    if (!p.children) return;
    zoom(p, p);
  }

.text(function(d){
      return d.depth == 1 ? d.name : "";
    })

}

// Zoom to the specified new root.
  function zoom(root, p) {
    svg.selectAll("text").data([]).exit().remove()
    if (document.documentElement.__transition__) return;

// Rescale outside angles to match the new layout.
    var enterArc,
        exitArc,
        outsideAngle = d3.scale.linear().domain([0, 2 * Math.PI]);

function insideArc(d) {
      return p.key > d.key
          ? {depth: d.depth - 1, x: 0, dx: 0} : p.key < d.key
          ? {depth: d.depth - 1, x: 2 * Math.PI, dx: 0}
          : {depth: 0, x: 0, dx: 2 * Math.PI};
    }

function outsideArc(d) {
      return {depth: d.depth + 1, x: outsideAngle(d.x), dx: outsideAngle(d.x + d.dx) - outsideAngle(d.x)};
    }

center.datum(root);

// When zooming in, arcs enter from the outside and exit to the inside.
    // Entering outside arcs start from the old layout.
    if (root === p) enterArc = outsideArc, exitArc = insideArc, outsideAngle.range([p.x, p.x + p.dx]);

path = path.data(partition.nodes(root).slice(1), function(d) { return d.key; });

// When zooming out, arcs enter from the inside and exit to the outside.
    // Exiting outside arcs transition to the new layout.
    if (root !== p) enterArc = insideArc, exitArc = outsideArc, outsideAngle.range([p.x, p.x + p.dx]);

d3.transition().duration(d3.event.altKey ? 7500 : 750).each(function() {
      path.exit().transition()
          .style("fill-opacity", function(d) { return d.depth === 1 + (root === p) ? 1 : 0; })
          .attrTween("d", function(d) { return arcTween.call(this, exitArc(d)); })
          .remove();

path.enter().append("path")
          .style("fill-opacity", function(d) { return d.depth === 2 - (root === p) ? 1 : 0; })
          .style("fill", function(d) { return colors[d.name]; })
          .on("click", zoomIn)
          //.text(function(d) { return d.data.key; });
          .each(function(d) { this._current = enterArc(d); });

path.transition()
          .style("fill-opacity", 1)
          .attrTween("d", function(d) { return arcTween.call(this, updateArc(d)); });
    });
  }
  
  
  //  ========== 
  //  = legend_lh = 
  //  ========== 
  var legend_data = [
/*"RU",
"FR",
"NL",
"CN",
"VG",
"CA",
"DE",
"JP",
"US",
"HK",
"BE",
"GB",
"MY",
"PL",
"KR"*/
"US",
"CN",
"FR",
"HK",
"DE",
"GB",
"JP",
"RU",
"CA",
"Others"
];
var legend_g =  svg_.append("g").attr("transform","translate("+(margin.left + margin.right -100)+",20)");
var legend_rect = legend_g.selectAll("rect").data(legend_data);
var legend_text = legend_g.selectAll("text").data(legend_data);
legend_rect.enter().append("rect")
.attr({
	"x":0,
	"y":function (d,i) {
	    return 10 * (i + 1) + (i * 20)
	},
	"width":20,
	"height":20,
	"fill":function (d) {
	    return colors[d];
	}
});

legend_text.enter().append("text")
.attr({
	"x":30,
	"y":function (d,i) {
	    return 10 * (i + 1) + (i * 20) + 15
	}
})
.text(function (d) {
    return d;
});

});

function key(d) {
  var k = [], p = d;
  while (p.depth) k.push(p.name), p = p.parent;
  return k.reverse().join(".");
}

function fill(d) {
  var p = d;
  while (p.depth > 1) p = p.parent;
  var c = d3.lab(hue(p.name));
  c.l = luminance(d.sum);
  return c;
}

function arcTween(b) {
  var i = d3.interpolate(this._current, b);
  this._current = i(0);
  return function(t) {
    return arc(i(t));
  };
}

function updateArc(d) {
  return {depth: d.depth, x: d.x, dx: d.dx};
}

d3.select(self.frameElement).style("height", margin.top + margin.bottom + "px");

</script>

Modified http://d3js.org/d3.v3.min.js to a secure url

https://d3js.org/d3.v3.min.js