Facebook Egonet

An example of a d3-force graph with 536 nodes and 9627 edges. The new canvas-based rendering is significantly faster than the SVG Force-Directed Graph.

To keep nodes on the screen, I tweaked the following forces:

Lowered the strength of the charge force and added a distanceMax
Added vertical and horizontal forces which help keep nodes from drifting offscreen with forceY and forceX

Facebook egonet data from Julian McAuley and Jure Leskovec.

forked from syntagmatic's block: Facebook Egonet

<!DOCTYPE html>
<meta charset="utf-8">
<canvas></canvas>
<script src="https://d3js.org/d3.v4.min.js"></script>
<script>
var width = 960,
    height = 600;

var canvas = d3.select("canvas")
    .attr("width", width)
    .attr("height", height);

var context = canvas.node().getContext("2d");

var simulation = d3.forceSimulation()
    .force("link", d3.forceLink().id(function(d) { return d.id; }))
    .force("charge", d3.forceManyBody().strength(-10).distanceMax(300))
    .force("center", d3.forceCenter(width / 2, height / 2))
    .force("vertical", d3.forceY().strength(0.018))
    .force("horizontal", d3.forceX().strength(0.006));

var graph = {};

d3.text("3437.edges", function(error, raw) {
  if (error) throw error;

var node_set = d3.set();

var pairs = raw.split("\n")
    .map(function(d) { return d.split(" "); });

pairs.forEach(function(d) {
    node_set.add(d[0]);
    node_set.add(d[1]);
  });

graph.nodes = node_set.values().map(function(d) {
    return {
      id: d
    };
  });

graph.links = pairs.map(function(d) {
    return {
      source: d[0],
      target: d[1]
    }
  });

simulation
      .nodes(graph.nodes)
      .on("tick", ticked);

simulation.force("link")
      .links(graph.links);

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

function ticked() {
    context.clearRect(0, 0, width, height);

context.beginPath();
    graph.links.forEach(drawLink);
    context.globalAlpha = 0.12;
    context.strokeStyle = "#999";
    context.stroke();

context.beginPath();
    graph.nodes.forEach(drawNode);
    context.globalAlpha = 1;
    context.fillStyle = d3.interpolateViridis(0.335);
    context.fill();
  }

function dragsubject() {
    return simulation.find(d3.event.x, d3.event.y);
  }
});

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 + 2.5, d.y);
  context.arc(d.x, d.y, 2.5, 0, 2 * Math.PI);
}

</script>

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