Bounded Force Layout - Columns by Depth

This example takes bjtucker's block: Bounded Force Layout - force rank by group and swaps out the dataset, showing energy flows from source to use.

This example also adds a Simple D3 tooltip. Hat tip to biovisualize for that bl.ock.

See another view of this energy flow data at the bl.ock Sankey Particles - Transparent Links

README.md from the original bl.ock

This D3 example shows how to constrain the position of nodes within the rectangular bounds of the containing SVG element. As a side-effect of updating the node's cx and cy attributes, we update the node positions to be within the range [radius, width - radius] for x, [radius, height - radius] for y. If you prefer, you could use the each operator to do this as a separate step, rather than as a side-effect of setting attributes.

Wrote the each operator step described above, but used tick to settle groups into separate ranks. -bjtucker

<!DOCTYPE html>
<meta charset="utf-8">
<style>

circle {
  stroke-width: 1.5px;
}

line {
  stroke: #999;
}

</style>
<body>
<script src="//d3js.org/d3.v3.min.js"></script>
<script>

var width = 960,
    height = 500,
    radius = 6;

var fill = d3.scale.category20();

var force = d3.layout.force()
    .gravity(0.05)
    .charge(-50) // -50
    .linkDistance(50)
    .size([width, height])
    .linkStrength(0.005)
    .friction(0.9)
    .theta(0.8)
    .alpha(0.1)

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

svg.append('rect')
  .attr("width", width)
  .attr("height", height)
  .style({
    fill: 'none',
    stroke: 'none',
    'stroke-width': 1
  });

d3.json("graph.json", function(error, graph) {
  if (error) throw error;
  
  var tooltip = d3.select("body")
		.append("div")
		.style("position", "absolute")
		.style("z-index", "10")
		.style("visibility", "hidden");
  
  var link = svg.selectAll("line")
      .data(graph.links)
    .enter().append("line");

var node = svg.selectAll("circle")
      .data(graph.nodes)
    .enter().append("circle")
      .attr("r", radius - .75)
      .style("fill", function(d) { return fill(d.depth); })
      .style("stroke", function(d) { return d3.rgb(fill(d.group)).darker(); })
      .call(force.drag);

force
      .nodes(graph.nodes)
      .links(graph.links)
      .on("tick", tick)
      .start();

function tick() {

node.each(function(d) { w = 105 * (1 + d.depth); d.x -= (0.2 * (d.x - w)) })

node.attr("cx", function(d) {return d.x = Math.max(radius, Math.min(width - radius, d.x)); })
        .attr("cy", function(d) {return d.y = Math.max(radius, Math.min(height - radius, d.y)); });

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
    .on("mouseover", function(d){
    	return tooltip
      	.text(d.name)
        .style("visibility", "visible");
  	})
		.on("mousemove", function(){
    	return tooltip
      	.style("top", (event.pageY - 10) + "px")
        .style("left",(event.pageX + 10) + "px");
  	})
		.on("mouseout", function(){
    	return tooltip
        .style("visibility", "hidden")
  	});
});

</script>

https://d3js.org/d3.v3.min.js