Ch. 5, Fig. 12 - D3.js in Action

This is the code for Chapter 5, Figure 12 from D3.js in Action which creates a circle pack diagram using d3.layout.pack() where the leaf nodes have different sizes based on the .value() function of the layout.

<html>
<head>
  <title>D3 in Action Chapter 5 - Example 5</title>
  <meta charset="utf-8" />
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js"></script>
</head>
<style>
  svg {
    height: 500px;
    width: 500px;
    border: 1px solid gray;
  }
  
</style>
<body>

<div id="viz">
  <svg>
  </svg>
</div>
</body>
  <footer>
    
<script>
    d3.json("tweets.json",function(error,data) {dataViz(data.tweets)});

function dataViz(incData) {

nestedTweets = d3.nest()
      .key(function (el) {return el.user})
      .entries(incData);

packableTweets = {id: "root", values: nestedTweets}

var depthScale = d3.scale.category10([0,1,2]);

exposedData = incData;
      packChart = d3.layout.pack();
      packChart.size([500,500])
      .children(function(d) {return d.values})
     .value(function(d) {return d.retweets.length + d.favorites.length + 1});

d3.select("svg")
      .append("g")
      .attr("transform", "translate(0,0)")
      .selectAll("circle")
      .data(packChart(packableTweets))
      .enter()
      .append("circle")
      .attr("r", function(d) {return d.r - (d.depth * 0)})
      .attr("cx", function(d) {return d.x})
      .attr("cy", function(d) {return d.y})
      .style("fill", function(d) {return depthScale(d.depth)})
      .style("stroke", "black")
      .style("stroke", "2px")
    }
    
</script>
  </footer>

</html>

https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js