Force-Directed Graph with Mouseover

<!DOCTYPE html>
<meta charset="utf-8">
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js"></script>
<style>

.link {
  fill: none;
  stroke: #666;
  stroke-width: 1.5px;
}

.node circle {
  fill: #ccc;
  stroke: #fff;
  stroke-width: 1.5px;
}

text {
  font: 10px sans-serif;
  pointer-events: none;
}

</style>
<body>
<script>

// https://blog.thomsonreuters.com/index.php/mobile-patent-suits-graphic-of-the-day/
var links = [
  {source: "Microsoft", target: "Amazon", type: "licensing"},
  {source: "Microsoft", target: "HTC", type: "licensing"},
  {source: "Samsung", target: "Apple", type: "suit"},
  {source: "Motorola", target: "Apple", type: "suit"},
  {source: "Nokia", target: "Apple", type: "resolved"},
  {source: "HTC", target: "Apple", type: "suit"},
  {source: "Kodak", target: "Apple", type: "suit"},
  {source: "Microsoft", target: "Barnes & Noble", type: "suit"},
  {source: "Microsoft", target: "Foxconn", type: "suit"},
  {source: "Oracle", target: "Google", type: "suit"},
  {source: "Apple", target: "HTC", type: "suit"},
  {source: "Microsoft", target: "Inventec", type: "suit"},
  {source: "Samsung", target: "Kodak", type: "resolved"},
  {source: "LG", target: "Kodak", type: "resolved"},
  {source: "RIM", target: "Kodak", type: "suit"},
  {source: "Sony", target: "LG", type: "suit"},
  {source: "Kodak", target: "LG", type: "resolved"},
  {source: "Apple", target: "Nokia", type: "resolved"},
  {source: "Qualcomm", target: "Nokia", type: "resolved"},
  {source: "Apple", target: "Motorola", type: "suit"},
  {source: "Microsoft", target: "Motorola", type: "suit"},
  {source: "Motorola", target: "Microsoft", type: "suit"},
  {source: "Huawei", target: "ZTE", type: "suit"},
  {source: "Ericsson", target: "ZTE", type: "suit"},
  {source: "Kodak", target: "Samsung", type: "resolved"},
  {source: "Apple", target: "Samsung", type: "suit"},
  {source: "Kodak", target: "RIM", type: "suit"},
  {source: "Nokia", target: "Qualcomm", type: "suit"}
];

var nodes = {};

// Compute the distinct nodes from the links.
links.forEach(function(link) {
  link.source = nodes[link.source] || (nodes[link.source] = {name: link.source});
  link.target = nodes[link.target] || (nodes[link.target] = {name: link.target});
});

var width = 960,
    height = 500;

var force = d3.layout.force()
    .nodes(d3.values(nodes))
    .links(links)
    .size([width, height])
    .linkDistance(60)
    .charge(-300)
    .on("tick", tick)
    .start();

var svg = d3.select("body").append("svg")
    .attr("width", width)
    .attr("height", height);

var link = svg.selectAll(".link")
    .data(force.links())
  .enter().append("line")
    .attr("class", "link");

var node = svg.selectAll(".node")
    .data(force.nodes())
  .enter().append("g")
    .attr("class", "node")
    .on("mouseover", mouseover)
    .on("mouseout", mouseout)
    .call(force.drag);

node.append("circle")
    .attr("r", 8);

node.append("text")
    .attr("x", 12)
    .attr("dy", ".35em")
    .text(function(d) { return d.name; });

node
      .attr("transform", function(d) { return "translate(" + d.x + "," + d.y + ")"; });
}

function mouseover() {
  d3.select(this).select("circle").transition()
      .duration(750)
      .attr("r", 16);
}

function mouseout() {
  d3.select(this).select("circle").transition()
      .duration(750)
      .attr("r", 8);
}

</script>

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