Question

<!DOCTYPE HTML>
<html lang="en">
  <head>
    <title>cartogram</title>
    <link rel="stylesheet" type="text/css" href="footprint.css"/>
    <script src="http://d3js.org/d3.v3.min.js" charset="utf-8"></script>
    <script src="http://d3js.org/queue.v1.min.js"></script>
    <script src="http://d3js.org/topojson.v1.min.js"></script>
    <script type="text/javascript" src="http://prag.ma/code/d3-cartogram/cartogram.js"></script>
    <script type="text/javascript" src="http://cdnjs.cloudflare.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
  </head>
  <body>
    <script type="text/javascript">
    var cartogram = d3.cartogram()
  .projection(d3.geo.albersUsa())
  .value(function(d) {
    return Math.random() * 100;
  });
 d3.json("http://zhicongchen.github.io/newsmap/data/china_cities_topo.json", function(topology) {
  var features = cartogram(topology, topology.objects.china_cities.geometries);
  d3.select("svg").selectAll("path")
    .data(features)
    .enter()
    .append("path")
      .attr("d", cartogram.path);
 });
 </script>
  </body>
</html>

我们尝试了上面的玩具代码，以便可视化中国城市的图表。但是，我们得到一个未捕获的TypeError：无法读取属性＆＃39; 0＆＃39;为null。有什么想法吗？

d3 topojson Uncaught TypeError：无法读取属性＆＃39; 0＆＃39;为null

0 个答案: