/ Network B
//

var networkB = svg.append("g");

networkB.append("rect")
    .attr("class", "background")
    .attr("width", width)
    .attr("height", nodeSizeB + 2 * nodeMargin)
    .attr("rx", nodeMargin * 0.7)
    .attr("ry", nodeMargin * 0.7);

var cellB = networkB.selectAll(".cell")
    .data(labelsB)
  .enter().append("g")
    .attr("class", "cell")
    .attr("transform", function(d, i) { return "translate(" + xb(i) + "," + nodeMargin + ")"; })
    .on("mouseover", function(d, i) {
      link.style("