Question

我是d3的初学者。我觉得特别有用和有趣的图表之一是d3力图。我一直在玩它，但出于某种原因，我对这个特定的数据集有很多麻烦。具体来说，我一直试图让标签显示在我的d3力图上，但它只是不起作用。这是我的代码：

 <!DOCTYPE html>
 <meta charset="utf-8">
 <style>
 .links line {
  stroke: #999;
  stroke-opacity: 0.6;
}
.nodes circle {
  stroke: #fff;
  stroke-width: 1.5px;
}
.node text {
  pointer-events: none;
  font: 10px sans-serif;
}

</style>
<svg width="960" height="600"></svg>
<script src="https://d3js.org/d3.v4.min.js"></script>
<script>
var svg = d3.select("svg"),
    width = +svg.attr("width"),
    height = +svg.attr("height");

var color = d3.scaleOrdinal(d3.schemeCategory20);

var simulation = d3.forceSimulation()
    .force("link", d3.forceLink().id(function(d) { return d.id; }))
    .force("charge", d3.forceManyBody())
    .force("center", d3.forceCenter(width / 2, height / 2));

d3.json("links.json", function(error, graph) {
  if (error) throw error;
  var link = svg.append("g")
      .attr("class", "links")
    .selectAll("line")
    .data(graph.links)
    .enter().append("line")
      .attr("stroke-width", function(d) { return 1});

  var node = svg.append("g")
      .attr("class", "nodes")
    .selectAll("circle")
    .data(graph.nodes)
    .enter().append("circle")
      .attr("r", function(d){
        return 3*d.size;
      })
      .attr("fill", function(d) { return color(d.id); })
      .call(d3.drag()
          .on("start", dragstarted)
          .on("drag", dragged)
          .on("end", dragended));

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

  simulation
      .nodes(graph.nodes)
      .on("tick", ticked);

  simulation.force("link")
      .links(graph.links);

  function ticked() {
    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("cx", function(d) { return d.x; })
        .attr("cy", function(d) { return d.y; });
  }
});

function dragstarted(d) {
  if (!d3.event.active) simulation.alphaTarget(0.3).restart();
  d.fx = d.x;
  d.fy = d.y;
}
function dragged(d) {
  d.fx = d3.event.x;
  d.fy = d3.event.y;
}
function dragended(d) {
  if (!d3.event.active) simulation.alphaTarget(0);
  d.fx = null;
  d.fy = null;
}
</script>

非常感谢你的帮助

编辑：这是我的links.json

{
  "nodes": [
  {"id": "AK","size": "1.414213562"},
  {"id": "AL","size": "1.414213562"},
  {"id": "AR","size": "1.414213562"},
  {"id": "AZ","size": "2.828427125"}],
"links": [
  {"source": "ABC","target": "CO","value": "A"},
  {"source": "ABC","target": "CO","value": "A"},
  {"source": "ABC","target": "CO","value": "A"},
  {"source": "ABC","target": "FL","value": "A"}
}

Answer 1

在下方添加了修改：

＆＃13;

var svg = d3.select("svg"),
    width = +svg.attr("width"),
    height = +svg.attr("height");

var color = d3.scaleOrdinal(d3.schemeCategory20);

var simulation = d3.forceSimulation()
    .force("link", d3.forceLink().id(function(d) { return d.id; }))
    .force("charge", d3.forceManyBody())
    .force("center", d3.forceCenter(width / 2, height / 2));

graph = {
  "nodes": [
  {"id": "AK","size": "1.414213562"},
  {"id": "AL","size": "1.414213562"},
  {"id": "AR","size": "1.414213562"},
  {"id": "AZ","size": "2.828427125"}],
"links": [
  {"source": "AK","target": "AL","value": "A"},
  {"source": "AL","target": "AZ","value": "A"},
  {"source": "AL","target": "AR","value": "A"},
  {"source": "AZ","target": "AR","value": "A"}]
};
  var link = svg.append("g")
      .attr("class", "links")
    .selectAll("line")
    .data(graph.links)
    .enter().append("line")
      .attr("stroke-width", function(d) { return 1});

  var node = svg.append("g")
      .attr("class", "nodes")
    .selectAll("circle")
    .data(graph.nodes)
    .enter().append("circle")
      .attr("r", function(d){
        return 5;
      })
      .attr("fill", function(d) { return color(d.id); })
      .call(d3.drag()
          .on("start", dragstarted)
          .on("drag", dragged)
          .on("end", dragended));

      node.append("svg:title")
      .attr("dx", 12)
      .attr("dy", ".35em")
      .text(function(d) { return d.id });
	
	var labels = svg.append("g")
      .attr("class", "label")
    .selectAll("text")
    .data(graph.nodes)
    .enter().append("text")
      .attr("dx", 6)
      .attr("dy", ".35em")
	   .style("font-size",10)
      .text(function(d) { return d.id });

	
  simulation
      .nodes(graph.nodes)
      .on("tick", ticked);

  simulation.force("link")
      .links(graph.links);

  function ticked() {
    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("cx", function(d) { return d.x; })
        .attr("cy", function(d) { return d.y; });
	  
	labels
        .attr("x", function(d) { return d.x; })
        .attr("y", function(d) { return d.y; });  
  }

function dragstarted(d) {
  if (!d3.event.active) simulation.alphaTarget(0.3).restart();
  d.fx = d.x;
  d.fy = d.y;
}
function dragged(d) {
  d.fx = d3.event.x;
  d.fy = d3.event.y;
}
function dragended(d) {
  if (!d3.event.active) simulation.alphaTarget(0);
  d.fx = null;
  d.fy = null;
}

＆＃13;

 .links line {
  stroke: #999;
  stroke-opacity: 0.6;
}
.nodes circle {
  stroke: #fff;
  stroke-width: 1.5px;
}
.node text {
  pointer-events: none;
  font: 10px sans-serif;
}

＆＃13;

<script src="https://d3js.org/d3.v4.min.js"></script>
<svg width="960" height="600"></svg>

＆＃13;

原始答案：

你的json不是＆＃34;正确＆＃34;。首先，没有名为ABC的源或名为CO或FL的目标。源和目标值应该是节点的id。您无法链接未定义的内容。您也没有使用size和value属性。

＆＃13;

var svg = d3.select("svg"),
    width = +svg.attr("width"),
    height = +svg.attr("height");

var color = d3.scaleOrdinal(d3.schemeCategory20);

var simulation = d3.forceSimulation()
    .force("link", d3.forceLink().id(function(d) { return d.id; }))
    .force("charge", d3.forceManyBody())
    .force("center", d3.forceCenter(width / 2, height / 2));

graph = {
  "nodes": [
  {"id": "AK","size": "1.414213562"},
  {"id": "AL","size": "1.414213562"},
  {"id": "AR","size": "1.414213562"},
  {"id": "AZ","size": "2.828427125"}],
"links": [
  {"source": "AK","target": "AL","value": "A"},
  {"source": "AL","target": "AZ","value": "A"},
  {"source": "AL","target": "AR","value": "A"},
  {"source": "AZ","target": "AR","value": "A"}]
};
  var link = svg.append("g")
      .attr("class", "links")
    .selectAll("line")
    .data(graph.links)
    .enter().append("line")
      .attr("stroke-width", function(d) { return 1});

  var node = svg.append("g")
      .attr("class", "nodes")
    .selectAll("circle")
    .data(graph.nodes)
    .enter().append("circle")
      .attr("r", function(d){
        return 5;
      })
      .attr("fill", function(d) { return color(d.id); })
      .call(d3.drag()
          .on("start", dragstarted)
          .on("drag", dragged)
          .on("end", dragended));

      node.append("svg:title")
      .attr("dx", 12)
      .attr("dy", ".35em")
      .text(function(d) { return d.id });

  simulation
      .nodes(graph.nodes)
      .on("tick", ticked);

  simulation.force("link")
      .links(graph.links);

  function ticked() {
    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("cx", function(d) { return d.x; })
        .attr("cy", function(d) { return d.y; });
  }

function dragstarted(d) {
  if (!d3.event.active) simulation.alphaTarget(0.3).restart();
  d.fx = d.x;
  d.fy = d.y;
}
function dragged(d) {
  d.fx = d3.event.x;
  d.fy = d3.event.y;
}
function dragended(d) {
  if (!d3.event.active) simulation.alphaTarget(0);
  d.fx = null;
  d.fy = null;
}

＆＃13;

 .links line {
  stroke: #999;
  stroke-opacity: 0.6;
}
.nodes circle {
  stroke: #fff;
  stroke-width: 1.5px;
}
.node text {
  pointer-events: none;
  font: 10px sans-serif;
}

＆＃13;

<script src="https://d3js.org/d3.v4.min.js"></script>
<svg width="960" height="600"></svg>

＆＃13;

标签不会出现在d3力图上

1 个答案: