block by emeeks aa5c8f08ad0900669917

Ch. 5, Fig. 17 - D3.js in Action

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This is the code for Chapter 5, Figure 17 from D3.js in Action that shows how to use d3.svg.diagonal.radial() and its .projection() function to create circular dendrograms. This also implements d3.behavior.zoom() so that you can pan the canvas by dragging.

index.html

<html>
<head>
  <title>D3 in Action Chapter 5 - Example 8</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]);

      treeChart = d3.layout.tree();
      treeChart.size([200,200])
      .children(function(d) {return d.values});

      var linkGenerator = d3.svg.diagonal.radial()
      .projection(function(d) { return [d.y, d.x / 180 * Math.PI]; });
  
      d3.select("svg")
      .append("g")
      .attr("class", "treeG")
      .selectAll("g")
      .data(treeChart(packableTweets))
      .enter()
      .append("g")
      .attr("class", "node")
      .attr("transform", function(d) { return "rotate(" + (d.x - 90) + ")translate(" + d.y + ")"; })
      
      d3.selectAll("g.node")
      .append("circle")
      .attr("r", 10)
      .style("fill", function(d) {return depthScale(d.depth)})
      .style("stroke", "white")
      .style("stroke-width", "2px");
      
      d3.selectAll("g.node")
      .append("text")
      .text(function(d) {return d.id || d.key || d.content})
      
      d3.select("g.treeG").selectAll("path")
      .data(treeChart.links(treeChart(packableTweets)))
      .enter().insert("path","g")
      .attr("d", linkGenerator)
      .style("fill", "none")
      .style("stroke", "black")
      .style("stroke-width", "2px");
      
      treeZoom = d3.behavior.zoom();
      treeZoom.on("zoom", zoomed);
      d3.select("svg").call(treeZoom)
      
      function zoomed() {
        var zoomTranslate = treeZoom.translate();
        d3.select("g.treeG").attr("transform", "translate("+zoomTranslate[0]+","+zoomTranslate[1]+")")
      }
    }
</script>
  </footer>

</html>

tweets.json

{
"tweets": [
{"user": "Al", "content": "I really love seafood.", "timestamp": " Mon Dec 23 2013 21:30 GMT-0800 (PST)", "retweets": ["Raj","Pris","Roy"], "favorites": ["Sam"]},
{"user": "Al", "content": "I take that back, this doesn't taste so good.", "timestamp": "Mon Dec 23 2013 21:55 GMT-0800 (PST)", "retweets": ["Roy"], "favorites": []},
{"user": "Al", "content": "From now on, I'm only eating cheese sandwiches.", "timestamp": "Mon Dec 23 2013 22:22 GMT-0800 (PST)", "retweets": [], "favorites": ["Roy","Sam"]},
{"user": "Roy", "content": "Great workout!", "timestamp": " Mon Dec 23 2013 7:20 GMT-0800 (PST)", "retweets": [], "favorites": []},
{"user": "Roy", "content": "Spectacular oatmeal!", "timestamp": " Mon Dec 23 2013 7:23 GMT-0800 (PST)", "retweets": [], "favorites": []},
{"user": "Roy", "content": "Amazing traffic!", "timestamp": " Mon Dec 23 2013 7:47  GMT-0800 (PST)", "retweets": [], "favorites": []},
{"user": "Roy", "content": "Just got a ticket for texting and driving!", "timestamp": " Mon Dec 23 2013 8:05 GMT-0800 (PST)", "retweets": [], "favorites": ["Sam", "Sally", "Pris"]},
{"user": "Pris", "content": "Going to have some boiled eggs.", "timestamp": " Mon Dec 23 2013 18:23 GMT-0800 (PST)", "retweets": [], "favorites": ["Sally"]},
{"user": "Pris", "content": "Maybe practice some gymnastics.", "timestamp": " Mon Dec 23 2013 19:47  GMT-0800 (PST)", "retweets": [], "favorites": ["Sally"]},
{"user": "Sam", "content": "@Roy Let's get lunch", "timestamp": " Mon Dec 23 2013 11:05 GMT-0800 (PST)", "retweets": ["Pris"], "favorites": ["Sally", "Pris"]}
]
}