Skip to content

Instantly share code, notes, and snippets.

@emeeks
Last active March 17, 2016 02:25
Show Gist options
  • Star 0 You must be signed in to star a gist
  • Fork 0 You must be signed in to fork a gist
  • Save emeeks/e330141d1279c6115a3a to your computer and use it in GitHub Desktop.
Save emeeks/e330141d1279c6115a3a to your computer and use it in GitHub Desktop.
Ch. 11, Fig. 10 - D3.js in Action

This is the code for Chapter 11, Figure 10 from D3.js in Action which uses mixed mode rendering to improve network performance via drawing nodes with SVG while drawing edges with HTML5 Canvas. This allows you to maintain mouse events on your nodes while dramatically improving animation performance.

<html>
<head>
<title>D3 in Action Chapter 11 - Example 6</title>
<meta charset="utf-8" />
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js"></script>
</head>
<style>
body, html {
margin: 0;
}
canvas {
position: absolute;
width: 500px;
height: 500px;
}
svg {
position: absolute;
width:500px;
height:500px;
}
path.country {
fill: gray;
stroke-width: 1;
stroke: black;
opacity: .5;
}
path.sample {
stroke: black;
stroke-width: 1px;
fill: red;
fill-opacity: .5;
}
line.link {
stroke-width: 1px;
stroke: black;
stroke-opacity: .5;
}
circle.node {
fill: red;
stroke: white;
stroke-width: 1px;
}
circle.xy {
fill: pink;
stroke: black;
stroke-width: 1px;
}
</style>
<body>
<canvas height="500" width="500"></canvas>
<div id="viz">
<svg></svg>
</div>
</body>
<footer>
<script>
var linkScale = d3.scale.linear().domain([0,.9,.95,1]).range([0,10,100,1000]);
sampleNodes = d3.range(3000).map(function(d) {
var datapoint = {};
datapoint.id = "Sample Node " + d;
return datapoint;
})
sampleLinks = [];
var y = 0;
while (y < 1000) {
var randomSource = Math.floor(Math.random() * 1000);
var randomTarget = Math.floor(linkScale(Math.random()));
var linkObject = {source: sampleNodes[randomSource], target: sampleNodes[randomTarget]}
if (randomSource != randomTarget) {
sampleLinks.push(linkObject);
}
y++;
}
force = d3.layout.force()
.size([500,500])
.gravity(.5)
.nodes(sampleNodes)
.links(sampleLinks)
.on("tick", forceTick);
d3.select("svg").selectAll("circle.node")
.data(sampleNodes)
.enter()
.append("circle")
.attr("r", 3)
.style("fill", "red")
.attr("class", "node")
.style("stroke", "white")
.style("stroke-width", "1px");
force.start();
function forceTick() {
var context = d3.select("canvas").node().getContext("2d");
context.clearRect(0,0,500,500);
context.lineWidth = 1;
context.strokeStyle = "rgba(0, 0, 0, 0.5)";
sampleLinks.forEach(function (link) {
context.beginPath();
context.moveTo(link.source.x,link.source.y)
context.lineTo(link.target.x,link.target.y)
context.stroke();
})
d3.selectAll("circle.node")
.attr("cx", function(d) {return d.x})
.attr("cy", function(d) {return d.y});
}
</script>
</footer>
</html>
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment