Force-Directed Tree II

<!DOCTYPE html>
<meta charset="utf-8">
<canvas width="960" height="640"></canvas>
<script src="https://d3js.org/d3.v4.min.js"></script>
<script>

var canvas = document.querySelector("canvas"),
    context = canvas.getContext("2d"),
    width = canvas.width,
    height = canvas.height;

d3.csv("d3.csv", function(error, data) {
  if (error) throw error;

var root = d3.stratify()
      .id(function(d) { return d.path; })
      .parentId(function(d) { return d.path.substring(0, d.path.lastIndexOf("/")); })
    (data);

var nodes = root.descendants(),
      links = root.links();

var simulation = d3.forceSimulation(nodes)
      .force("charge", d3.forceManyBody())
      .force("link", d3.forceLink(links).strength(1))
      .force("x", d3.forceX())
      .force("y", d3.forceY())
      .on("tick", ticked);

d3.select(canvas)
      .call(d3.drag()
          .container(canvas)
          .subject(dragsubject)
          .on("start", dragstarted)
          .on("drag", dragged)
          .on("end", dragended));

function ticked() {
    context.clearRect(0, 0, width, height);
    context.save();
    context.translate(width / 2, height / 2);

context.beginPath();
    links.forEach(drawLink);
    context.strokeStyle = "#aaa";
    context.stroke();

context.beginPath();
    nodes.forEach(drawNode);
    context.fill();
    context.strokeStyle = "#fff";
    context.stroke();

context.restore();
  }

function dragsubject() {
    return simulation.find(d3.event.x - width / 2, d3.event.y - height / 2);
  }

function dragstarted() {
    if (!d3.event.active) simulation.alphaTarget(0.3).restart();
    d3.event.subject.fx = d3.event.subject.x;
    d3.event.subject.fy = d3.event.subject.y;
  }

function dragged() {
    d3.event.subject.fx = d3.event.x;
    d3.event.subject.fy = d3.event.y;
  }

function dragended() {
    if (!d3.event.active) simulation.alphaTarget(0);
    d3.event.subject.fx = null;
    d3.event.subject.fy = null;
  }

function drawLink(d) {
    context.moveTo(d.source.x, d.source.y);
    context.lineTo(d.target.x, d.target.y);
  }

function drawNode(d) {
    context.moveTo(d.x + 3, d.y);
    context.arc(d.x, d.y, 3, 0, 2 * Math.PI);
  }
});

</script>

https://d3js.org/d3.v4.min.js