d3.js v4：尝试修复图节点的子集

Question

I would like to set some nodes of a graph fixed. For this I have an array with node names which should be fixed:

selectedNodes = ["id0","id4","ide7"];

Next, I have the complete set of nodes:

allNodes = graph.data;

Following is my attempt to change the state.

for (var i = 0; i < allNodes.length; i++) {
    d3.select(allNodes[i]);
    if (nodeList.indexOf(allNodes[i].id > -1)) {
        allNodes[i].fixed = true;
    } else {
        allNodes[i].fixed = false;  
    };
}

This does not work. And I have hit a dead end. Does anybody know what is going on? How can I set only fix a certain of number nodes?

Answer 1

You should not change the data array (besides that, using d3.select to manipulate the data array doesn't make sense). Instead of that, change the bound datum .

Since you didn't provide your force layout, I'll use this one from Bostock, which uses D3 v3, like yours.

I'll fix the positions of three Les Miserables' characters:

var selectedNodes = ["Brujon", "Gervais", "Javert"]; 

To do that, we change the datum in an each :

node.each(function(d) {
    if (selectedNodes.indexOf(d.name) > -1) {
        d.fixed = true;
    }
})

And here is the code with that change: https://bl.ocks.org/anonymous/7b02643ba27e5323d30447579a38f58a/2ef2fb7568021a1082aa959891a2d05fab6bad9e

You can see that those three are fixed now.

Answer 2

Here is the code.

Kind regards, Markus

<script src="//d3js.org/d3.v3.min.js"></script>
<script>

    var width = 960,
    height = 500;

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

var force = d3.layout.force()
    .gravity(0.05)
    .distance(100)
    .charge(-100)
    .size([width, height]);

d3.json("graph.json", function(error, json) {
  if (error) throw error;

  force
      .nodes(json.nodes)
      .links(json.links)
      .start();

  var link = svg.selectAll(".link")
      .data(json.links)
    .enter().append("line")
      .attr("class", "link");

  var node = svg.selectAll(".node")
      .data(json.nodes)
    .enter().append("g")
      .attr("class", "node")
      .call(force.drag);

  node.append("image")
      .attr("xlink:href", "https://github.com/favicon.ico")
      .attr("x", -8)
      .attr("y", -8)
      .attr("width", 16)
      .attr("height", 16);

  node.append("text")
      .attr("dx", 12)
      .attr("dy", ".35em")
      .text(function(d) { return d.name });

  svg.on("dblclick", function(d) {
     var selectedNodes = ["Brujon", "Gervais", "Javert"];

     node.each(function(d){
           if(selectedNodes.indexOf(d.name) > -1){
        d.fixed = true
        console.log(d)
        }

      force
      .nodes(json.nodes)
      .links(json.links)
      .start();


    createLayout(force, link, node);

  })


  });

  createLayout(force, link, node);

});

function createLayout(force, link, node) {


  force.on("tick", function() {
    link.attr("x1", function(d) { return d.source.x; })
        .attr("y1", function(d) { return d.source.y; })
        .attr("x2", function(d) { return d.target.x; })
        .attr("y2", function(d) { return d.target.y; });

    node.attr("transform", function(d) { return "translate(" + d.x + "," + d.y + ")"; });
  });


};