Function force

external/.d3.js:8407–8421

()

  if (y == null) y = 0;

  function force() {
    var i,
        n = nodes.length,
        node,
        sx = 0,
        sy = 0;

    for (i = 0; i < n; ++i) {
      node = nodes[i], sx += node.x, sy += node.y;
    }

    for (sx = (sx / n - x) * strength, sy = (sy / n - y) * strength, i = 0; i < n; ++i) {
      node = nodes[i], node.x -= sx, node.y -= sy;
    }
  }

  force.initialize = function(_) {
    nodes = _;