Question

我是D3的新手，我只是在试验它的功能。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强制导向图。我的代码如下。

非常感谢任何帮助

$date = date('Y-m-d', strtotime($line[0]));  
// convert date to yyyy-mm-dd

Answer 1

这非常简单并且展示了here。你有一个力模拟并不重要，步骤是一样的。

这是它集成到您的示例代码中：

<!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强制定向图变焦

1 个答案: