传单地图上的 d3 圆圈

我使用以下代码生成带有圆圈的地图；

http://jsbin.com/OTaKEDor/2/edit http://jsbin.com/OTaKEDor/2/edit

<script src="http://d3js.org/d3.v3.min.js"></script>
<link rel="stylesheet" href="http://cdn.leafletjs.com/leaflet-0.6.4/leaflet.css" />
<script src="http://cdnjs.cloudflare.com/ajax/libs/d3/3.3.9/d3.min.js"></script>
<script src="http://cdn.leafletjs.com/leaflet-0.6.4/leaflet.js"></script>

<script type='text/javascript' id='lt_ws' src='http://localhost:52656/socket.io/lighttable/ws.js'></script>

<div id="map" style="width: 100%; height: 100%; position: relative;" class="leaflet-container leaflet-fade-anim" tabindex="0">
</div>

<script>
    var map = L.map('map').setView([51.82, 5.861], 11); 
  L.tileLayer('http://{s}.tile.cloudmade.com/BC9A493B41014CAABB98F0471D759707/997/256/{z}/{x}/{y}.png', {
      maxZoom: 18,
      attribution: ''
  }).addTo(map);

  var data = [ [5.861797,51.822823],[5.861843,51.822815],[5.5102863,51.78242],[5.8564305,51.821033],[5.859349,51.822502] ];

  var plotData = data.map( function( coord ){ 
    return map.latLngToLayerPoint( [ coord[1], coord[0] ] );
  });

  var svg = d3.select( map.getPanes().overlayPane ).append("svg"), 
      g   = svg.append("g").attr("class", "leaflet-zoom-hide");

  g.selectAll("circle").data( plotData ).enter().append("circle")
    .attr("cx", function(d){ return d.x; } )
    .attr("cy", function(d){ return d.y; } )
    .attr("r", 25)
    .style("fill", "black");

</script>

我将坐标映射到传单，以便将其放置在正确的位置。问题是圆圈被放置在传单地图上的 svg 上，谷歌开发工具证实了这一点，但它们没有获得正确的属性，它们仍然不可见。

见截图；

有什么我忘记做的事情吗？

这有效，这也是更好的代码，现在数据绑定到 svg 元素，这允许更多的交互性；

function drawCircles(){
  var data = [
    { "coords" : [ 37.8 , - 96.8 ], "time" : 1 },
    { "coords" : [ 33.6 , - 96.6 ], "time" : 5 },
    { "coords" : [ 40.5 , - 96.3 ], "time" : 4 },
    { "coords" : [ 37.4 , - 66.6 ], "time" : 3 },
    { "coords" : [ 37.8 , - 97.6 ], "time" : 2 }
  ].map( function(d){ var newPoint = map.latLngToLayerPoint( d.coords ); d.coords = { 'x' : newPoint.x, 'y' : newPoint.y }; return d; } )

  g.selectAll("circle").data( data ).enter().append("circle")
    .attr("cx", function(d){ console.log(d); return d.coords.x } )
    .attr("cy", function(d){ return d.coords.y } )
    .attr("r", 5 )
    .style("fill", "teal")
}