var json = JSON.parse( myjson );

var width = 950,
    height = 950;

var colors = d3.scale.category20();

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

var force = d3.layout.force()
    .charge(-300)
    .linkDistance(40)
    .size([width, height]);
 
var link = svg.selectAll(".link")
        .data(json.links)
	    .enter().append("line")
	      .attr("class", "link");

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

node.append("circle")
	        .attr("r", function(d) { return d.size; } )
	        .attr("fill", function(d) { return colors(d.group); } );

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

force.on("tick", function() {
	    link.attr("x1", function(d) { return d.source.x; })
	        .attr("y1", function(d) { return d.source.y; })
	        .attr("x2", function(d) { return d.target.x; })
	        .attr("y2", function(d) { return d.target.y; });

	    node.attr("transform", function(d) { return "translate(" + d.x + "," + d.y + ")"; });
});
  
force.nodes(json.nodes)
      .links(json.links)
      .start();
</script>

<p>The following graph was created using the R package <tt>popgraph</tt>. Any questions or comments can be sent to rjdyer@vcu.edu</p>
</body>
</html>