Dynamic Force Layout

<!DOCTYPE html>
<meta charset="utf-8">
<body>
<script src="https://d3js.org/d3.v3.min.js"></script>
<script>

var w = 960,
    h = 500,
    nodes = [],
    node;

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

var force = d3.layout.force()
    .nodes(nodes)
    .links([])
    .size([w, h]);

force.on("tick", function(e) {
  vis.selectAll("path")
      .attr("transform", function(d) { return "translate(" + d.x + "," + d.y + ")"; });
});

setInterval(function(){

// Add a new random shape.
  nodes.push({
    type: "circle",//d3.svg.symbolTypes[~~(Math.random() * d3.svg.symbolTypes.length)],
    size: Math.random() * 300 + 100
  });

// Restart the layout.
  force.start();

vis.selectAll("path")
      .data(nodes)
    .enter().append("path")
      .attr("transform", function(d) { return "translate(" + d.x + "," + d.y + ")"; })
      .attr("d", d3.svg.symbol()
        .size(function(d) { return d.size; })
        .type(function(d) { return d.type; }))
      .style("fill", "steelblue")
      .style("stroke", "transparent")
      .style("stroke-width", "15")
      .call(force.drag);

}, 1000);

</script>

Modified http://d3js.org/d3.v3.min.js to a secure url

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