Force-based label placement

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
	<head>
		<meta charset="utf-8">
		<title>Force based label placement</title>
		<script type="text/javascript" src="https://cdn.jsdelivr.net/npm/d3@2.6.0/d3.js"></script>
		<script type="text/javascript" src="https://cdn.jsdelivr.net/npm/d3@2.6.0/d3.layout.js"></script>
		<script type="text/javascript" src="https://cdn.jsdelivr.net/npm/d3@2.6.0/d3.geom.js"></script>
	</head>
	<body>
<script type="text/javascript" charset="utf-8">
			var w = 960, h = 500;

var labelDistance = 0;

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

var nodes = [];
			var labelAnchors = [];
			var labelAnchorLinks = [];
			var links = [];

for(var i = 0; i < 30; i++) {
				var node = {
					label : "node " + i
				};
				nodes.push(node);
				labelAnchors.push({
					node : node
				});
				labelAnchors.push({
					node : node
				});
			};

for(var i = 0; i < nodes.length; i++) {
				for(var j = 0; j < i; j++) {
					if(Math.random() > .95)
						links.push({
							source : i,
							target : j,
							weight : Math.random()
						});
				}
				labelAnchorLinks.push({
					source : i * 2,
					target : i * 2 + 1,
					weight : 1
				});
			};

var force = d3.layout.force().size([w, h]).nodes(nodes).links(links).gravity(1).linkDistance(50).charge(-3000).linkStrength(function(x) {
				return x.weight * 10
			});

force.start();

var force2 = d3.layout.force().nodes(labelAnchors).links(labelAnchorLinks).gravity(0).linkDistance(0).linkStrength(8).charge(-100).size([w, h]);
			force2.start();

var link = vis.selectAll("line.link").data(links).enter().append("svg:line").attr("class", "link").style("stroke", "#CCC");

var node = vis.selectAll("g.node").data(force.nodes()).enter().append("svg:g").attr("class", "node");
			node.append("svg:circle").attr("r", 5).style("fill", "#555").style("stroke", "#FFF").style("stroke-width", 3);
			node.call(force.drag);

var anchorLink = vis.selectAll("line.anchorLink").data(labelAnchorLinks)//.enter().append("svg:line").attr("class", "anchorLink").style("stroke", "#999");

var anchorNode = vis.selectAll("g.anchorNode").data(force2.nodes()).enter().append("svg:g").attr("class", "anchorNode");
			anchorNode.append("svg:circle").attr("r", 0).style("fill", "#FFF");
				anchorNode.append("svg:text").text(function(d, i) {
				return i % 2 == 0 ? "" : d.node.label
			}).style("fill", "#555").style("font-family", "Arial").style("font-size", 12);

}

var updateNode = function() {
				this.attr("transform", function(d) {
					return "translate(" + d.x + "," + d.y + ")";
				});

}

force.on("tick", function() {

force2.start();

node.call(updateNode);

anchorNode.each(function(d, i) {
					if(i % 2 == 0) {
						d.x = d.node.x;
						d.y = d.node.y;
					} else {
						var b = this.childNodes[1].getBBox();

var diffX = d.x - d.node.x;
						var diffY = d.y - d.node.y;

var dist = Math.sqrt(diffX * diffX + diffY * diffY);

var shiftX = b.width * (diffX - dist) / (dist * 2);
						shiftX = Math.max(-b.width, Math.min(0, shiftX));
						var shiftY = 5;
						this.childNodes[1].setAttribute("transform", "translate(" + shiftX + "," + shiftY + ")");
					}
				});

anchorNode.call(updateNode);

link.call(updateLink);
				anchorLink.call(updateLink);

});

</script>
	</body>
</html>

Modified http://mbostock.github.com/d3/d3.js?2.6.0 to a secure url

Modified http://mbostock.github.com/d3/d3.layout.js?2.6.0 to a secure url

Modified http://mbostock.github.com/d3/d3.geom.js?2.6.0 to a secure url

https://mbostock.github.com/d3/d3.js?2.6.0

https://mbostock.github.com/d3/d3.layout.js?2.6.0

https://mbostock.github.com/d3/d3.geom.js?2.6.0