Function pack

d3-3.2.8/d3.js:6279–6300

(d, i)

  d3.layout.pack = function() {
    var hierarchy = d3.layout.hierarchy().sort(d3_layout_packSort), padding = 0, size = [ 1, 1 ], radius;
    function pack(d, i) {
      var nodes = hierarchy.call(this, d, i), root = nodes[0], w = size[0], h = size[1], r = radius == null ? Math.sqrt : typeof radius === "function" ? radius : function() {
        return radius;
      };
      root.x = root.y = 0;
      d3_layout_treeVisitAfter(root, function(d) {
        d.r = +r(d.value);
      });
      d3_layout_treeVisitAfter(root, d3_layout_packSiblings);
      if (padding) {
        var dr = padding * (radius ? 1 : Math.max(2 * root.r / w, 2 * root.r / h)) / 2;
        d3_layout_treeVisitAfter(root, function(d) {
          d.r += dr;
        });
        d3_layout_treeVisitAfter(root, d3_layout_packSiblings);
        d3_layout_treeVisitAfter(root, function(d) {
          d.r -= dr;
        });
      }
      d3_layout_packTransform(root, w / 2, h / 2, radius ? 1 : 1 / Math.max(2 * root.r / w, 2 * root.r / h));
      return nodes;
    }
    pack.size = function(_) {
      if (!arguments.length) return size;
      size = _;