Sigma-js无法加载外部gexf

从https://github.com/jacomyal/sigma.js尝试gexf文件的基本加载。不幸的是，html-load-eternal-gexf.html没有加载任何图形。

    <!-- START SIGMA IMPORTS -->
<script src="../src/sigma.core.js"></script>
<script src="../src/conrad.js"></script>
<script src="../src/utils/sigma.utils.js"></script>
<script src="../src/utils/sigma.polyfills.js"></script>
<script src="../src/sigma.settings.js"></script>
<script src="../src/classes/sigma.classes.dispatcher.js"></script>
<script src="../src/classes/sigma.classes.configurable.js"></script>
<script src="../src/classes/sigma.classes.graph.js"></script>
<script src="../src/classes/sigma.classes.camera.js"></script>
<script src="../src/classes/sigma.classes.quad.js"></script>
<script src="../src/captors/sigma.captors.mouse.js"></script>
<script src="../src/captors/sigma.captors.touch.js"></script>
<script src="../src/renderers/sigma.renderers.canvas.js"></script>
<script src="../src/renderers/sigma.renderers.webgl.js"></script>
<script src="../src/renderers/sigma.renderers.def.js"></script>
<script src="../src/renderers/webgl/sigma.webgl.nodes.def.js"></script>
<script src="../src/renderers/webgl/sigma.webgl.nodes.fast.js"></script>
<script src="../src/renderers/webgl/sigma.webgl.edges.def.js"></script>
<script src="../src/renderers/webgl/sigma.webgl.edges.fast.js"></script>
<script src="../src/renderers/webgl/sigma.webgl.edges.arrow.js"></script>
<script src="../src/renderers/canvas/sigma.canvas.labels.def.js"></script>
<script src="../src/renderers/canvas/sigma.canvas.hovers.def.js"></script>
<script src="../src/renderers/canvas/sigma.canvas.nodes.def.js"></script>
<script src="../src/renderers/canvas/sigma.canvas.edges.def.js"></script>
<script src="../src/renderers/canvas/sigma.canvas.edges.curve.js"></script>
<script src="../src/renderers/canvas/sigma.canvas.edges.arrow.js"></script>
<script src="../src/renderers/canvas/sigma.canvas.edges.curvedArrow.js"></script>
<script src="../src/middlewares/sigma.middlewares.rescale.js"></script>
<script src="../src/middlewares/sigma.middlewares.copy.js"></script>
<script src="../src/misc/sigma.misc.animation.js"></script>
<script src="../src/misc/sigma.misc.bindEvents.js"></script>
<script src="../src/misc/sigma.misc.drawHovers.js"></script>
<!-- END SIGMA IMPORTS -->
<script src="../plugins/sigma.parsers.gexf/gexf-parser.js"></script>
<script src="../plugins/sigma.parsers.gexf/sigma.parsers.gexf.js"></script>
<div id="container">
  <style>
    #graph-container {
      top: 0;
      bottom: 0;
      left: 0;
      right: 0;
      position: absolute;
    }
  </style>
  <div id="graph-container"></div>
</div>
<script>
/**
 * Here is just a basic example on how to properly display a graph
 * exported from Gephi in the GEXF format.
 *
 * The plugin sigma.parsers.gexf can load and parse the GEXF graph file,
 * and instantiate sigma when the graph is received.
 *
 * The object given as the second parameter is the base of the instance
 * configuration object. The plugin will just add the "graph" key to it
 * before the instanciation.
 */
sigma.parsers.gexf('data/arctic.gexf', {
  container: 'graph-container'
});
</script>

arctic.gexf文件也位于数据目录下。我正在使用谷歌chrome 37

怎么了？我可以在example目录下加载其他example htmls，但load-external-json.html也不起作用。