Multi-foci d3 force layout, based on data

index.js

force.on("tick", function(e) {

  // Push nodes toward their designated focus.
  var k = .1 * e.alpha;
  nodes.forEach(function(o, i) {
    o.y += (foci[o.id].y - o.y) * k;
    o.x += (foci[o.id].x - o.x) * k;
  });

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