如何在D3部队布局中突出显示/选择邻居的邻居

我用它来帮助突出显示相邻节点：

http://jsfiddle.net/simonraper/jz2AU/light/

var toggle = 0;//Toggle stores whether the highlighting is on
var linkedByIndex = {};//Create an array logging what is connected to what
for (i = 0; i < network.network.data.nodes.length; i++) //-populate the array
{
    linkedByIndex[i + "," + i] = 1;
};
network.network.data.edges.forEach(function (d) //-checks what nodes are related in array
{
    linkedByIndex[d.source.index + "," + d.target.index] = 1;
});
//-------------------------check if nodes are linked
function neighboring(a, b) //This function looks up whether a pair are neighbours
{
    return linkedByIndex[a.index + "," + b.index];
}
//-------------------------finds out connected nodes, keeps their styles but changes the opacity of every other
function connectedNodes() {
//Reduce the opacity of all but the neighbouring nodes
d = d3.select(this).node().__data__;
    if (toggle == 0) { 
        // nodes.classed("highlighted", function (o) {
            // return neighboring(d, o) | neighboring(o, d) ? true : false;
        // });      
        nodes.style("opacity", function (o) {
            return neighboring(d, o) | neighboring(o, d) ? 1 : 0.1;
        });
        links.style("opacity", function (o) {
            return d.index==o.source.index | d.index==o.target.index ? 1 : 0.1;
        });
        //Reduce the op
        toggle = 1;
    } else {
        //Put them back to opacity=1
        nodes.style("opacity", 1);
        links.style("opacity", 1);
        nodes.classed("highlighted", false);
        toggle = 0;
    }
}

这样做的作用是双击节点时，所选节点及其相邻节点保持其不透明度，而所有其他节点降低其不透明度。

现在，当我双击第一个选定节点的子节点之一时，整个选择都会消失(所有节点的不透明度为 1(。

我希望拥有的是，当我双击其中一个子节点时，选择不会消失，该子节点的相关节点现在变得"突出显示"。

这样做将有助于指导我轻松完成力定向图，尤其是对于大量数据。