D3.js V4 Force Directed Graph Zoom

Question

我是 D3 的新手，只是在试验它的功能。请原谅我，如果这已经被覆盖，但我似乎无法找到一种方法来实现缩放到我的 D3.js v4 强制定向图。我的代码如下。

如有任何帮助，我们将不胜感激

<!DOCTYPE html>
<meta charset="utf-8">
<style>

.links line {
 stroke: #999;
 stroke-opacity: 0.6;
}

.nodes circle {
 stroke: #fff;
 stroke-width: 1.5px;
}

</style>
<div class="centre jumbotron">
 <h1> Title </h1>
  <h2>
   This is the home page
  </h2>
</div>
<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("network_data#all", 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 Math.sqrt(d.value); });

 var node = svg.append("g")
  .attr("class", "nodes")
  .selectAll("circle")
  .data(graph.nodes)
  .enter().append("circle")
  .attr("r", 5)
  .attr("fill", function(d) { return color(d.group); })
  .call(d3.drag()
    .on("start", dragstarted)
    .on("drag", dragged)
    .on("end", dragended));

 node.append("title")
  .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>

Answer 1

它非常简单明了并且经过演示 here。你有一个力模拟并不重要，步骤是一样的。

这是集成到您示例代码中的它：

<!DOCTYPE html>
<meta charset="utf-8">
<style>
  .links line {
    stroke: #999;
    stroke-opacity: 0.6;
  }
  
  .nodes circle {
    stroke: #fff;
    stroke-width: 1.5px;
  }
</style>
<div class="centre jumbotron">
 <h1> Title </h1>
  <h2>
   This is the home page
  </h2>
</div>
<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");
    
  svg.append("rect")
    .attr("width", width)
    .attr("height", height)
    .style("fill", "none")
    .style("pointer-events", "all")
    .call(d3.zoom()
      .scaleExtent([1 / 2, 4])
      .on("zoom", zoomed));

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

  function zoomed() {
    g.attr("transform", d3.event.transform);
  }

  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("https://jsonblob.com/api/6e520635-d35c-11e6-b16a-6b255c15b1a3", function(error, graph) {
    if (error) throw error;

    var link = g.append("g")
      .attr("class", "links")
      .selectAll("line")
      .data(graph.links)
      .enter().append("line")
      .attr("stroke-width", function(d) {
        return Math.sqrt(d.value);
      });

    var node = g.append("g")
      .attr("class", "nodes")
      .selectAll("circle")
      .data(graph.nodes)
      .enter().append("circle")
      .attr("r", 5)
      .attr("fill", function(d) {
        return color(d.group);
      })
      .call(d3.drag()
        .on("start", dragstarted)
        .on("drag", dragged)
        .on("end", dragended));

    node.append("title")
      .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>

D3.js V4 Force Directed Graph Zoom

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