Force-Directed Graph

Force-directed layout of graph info in D3.js v4

forked from Mike Bostock's original here: https://bl.ocks.org/mbostock/4062045

Data captures relationships between staff members at UoN Psychology.

<!DOCTYPE html>
<meta charset="utf-8">
<style>
  .links line {
    stroke: #999;
    stroke-opacity: 0.6;
  }

.nodes circle {
    stroke: #fff;
    stroke-width: 1.5px;
  }
</style>
<svg width="960" height="600"></svg>
<script src="https://d3js.org/d3.v4.min.js"></script>
<script>
  var svg = d3.select("svg"),
    width = +svg.attr("width"),
    height = +svg.attr("height");

var filename = 'psychology.json';
  var pSize = 10, apSize = 5; // profs and a-profs

var color = d3.scaleOrdinal(d3.schemeCategory10);

var simulation = d3.forceSimulation()
    .force("link", d3.forceLink().id(function(d) {
      return d.id;
    }))
    .force("charge", d3.forceManyBody().strength(-10))
    .force("center", d3.forceCenter(width / 2, height / 2));

d3.json(filename, function(error, graph) {
    if (error) throw error;

var link = svg.append("g")
      .attr("class", "links")
      .selectAll("line")
      .data(graph.links)
      .enter().append("line")
      .attr("stroke-width", function(d) {
        return Math.sqrt(d.value);
      });

var node = svg.append("g")
      .attr("class", "nodes")
      .selectAll("circle")
      .data(graph.nodes)
      .enter().append("circle")
      .attr("r", function (d) { return d.title == "Prof" ? pSize : apSize;}  )
      .attr("fill", function(d) {
        return color(d.group);
      })
      .call(d3.drag()
        .on("start", dragstarted)
        .on("drag", dragged)
        .on("end", dragended));

node.append("title")
      .text(function(d) {
        return d.title;
      });

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

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

node
        .attr("cx", function(d) {
          return d.x;
        })
        .attr("cy", function(d) {
          return d.y;
        });
    }
  });

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

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

function dragended(d) {
    if (!d3.event.active) simulation.alphaTarget(0);
    d.fx = null;
    d.fy = null;
  }
</script>

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