d3js在线元素中插入圆形形状有效图形？

Question

我试图在我的力量有向图中添加会出现在节点（可能居中）之间的线上的红色圆圈。

我试着将它添加到line.link类似解决它喜欢我加入线，以新的变量：

var linkcirc = vis.selectAll("line.link") 
      .data(data.links) 
      .enter().append("circle") 
      .attr("r",5) 
      .attr("cy", function(d) { return d.target.y; }) 
      .attr("cx", function(d) { return d.source.x+60; }) 
      .attr("class", "linecircle") 
      .attr("fill","red"); 

和力蜱我说：

linkcirc.attr("cy", function(d) { return d.target.y; }) 
      .attr("cx", function(d) { return d.source.x+60; }) 

他们这样做出现，但我不知道如何将它们放置在正确的位置，在节点的中间......如何使用源，目标位置或其他内容，以便红色圆圈显示在链接的中心？...

你可以看到我的情况现在在这里：http://jsfiddle.net/nAAbn/

和脚本如下所示：

var data = {"nodes":[ 
         {"name":"YHO", "full_name":"Yahoo", "type":1, "slug": "www.yahoo.com", "entity":"company", "img_hrefD":"", "img_hrefL":""}, 
         {"name":"GGL", "full_name":"Google", "type":2, "slug": "www.google.com", "entity":"company", "img_hrefD":"", "img_hrefL":""}, 
         {"name":"BNG", "full_name":"Bing", "type":2, "slug": "www.bing.com", "entity":"company", "img_hrefD":"", "img_hrefL":""}, 
         {"name":"YDX", "full_name":"Yandex", "type":2, "slug": "www.yandex.com", "entity":"company", "img_hrefD":"", "img_hrefL":""}, 

         {"name":"Desc1", "type":4, "slug": "", "entity":"description"}, 
         {"name":"Desc2", "type":4, "slug": "", "entity":"description"}, 
         {"name":"Desc4", "type":4, "slug": "", "entity":"description"}, 

         {"name":"CEO", "prefix":"Mr.", "fst_name":"Jim", "snd_name":"Bean", "type":3, "slug": "", "entity":"employee"}, 
         {"name":"ATT", "prefix":"Ms.", "fst_name":"Jenna", "snd_name":"Jameson", "type":3, "slug": "", "entity":"employee"}, 
         {"name":"CTO", "prefix":"Mr.", "fst_name":"Lucky", "snd_name":"Luke", "type":3, "slug": "", "entity":"employee"}, 
         {"name":"CDO", "prefix":"Ms.", "fst_name":"Pamela", "snd_name":"Anderson", "type":3, "slug": "", "entity":"employee"}, 
         {"name":"CEO", "prefix":"Mr.", "fst_name":"Nacho", "snd_name":"Vidal", "type":3, "slug": "", "entity":"employee"}, 
        ], 
      "links":[ 
         {"source":0,"target":4,"value":1,"distance":5}, 
         {"source":0,"target":5,"value":1,"distance":5}, 
         {"source":0,"target":6,"value":1,"distance":5}, 

         {"source":1,"target":4,"value":1,"distance":5}, 
         {"source":2,"target":5,"value":1,"distance":5}, 
         {"source":3,"target":6,"value":1,"distance":5}, 

         {"source":7,"target":3,"value":10,"distance":6}, 
         {"source":8,"target":3,"value":10,"distance":6}, 
         {"source":9,"target":1,"value":10,"distance":6}, 
         {"source":10,"target":1,"value":10,"distance":6}, 
         {"source":11,"target":2,"value":10,"distance":6}, 
         ] 
       }  



    var w = 560, 
     h = 500, 
     radius = d3.scale.log().domain([0, 312000]).range(["10", "50"]); 

    var vis = d3.select("body").append("svg:svg") 
     .attr("width", w) 
     .attr("height", h); 


    //d3.json(data, function(json) { 
     var force = self.force = d3.layout.force() 
      .nodes(data.nodes) 
      .links(data.links) 
      .linkDistance(function(d) { return (d.distance*20); }) 
      //.friction(0.5) 
      .charge(-250) 
      .size([w, h]) 
      .start(); 



     var link = vis.selectAll("line.link") 
      .data(data.links) 
      .enter().append("svg:line") 
      .style("stroke","blue") 
      .attr("class", function (d) { return "link" + d.value +""; }) 
      .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; }) 


     var linkcirc = vis.selectAll("line.link") 
      .data(data.links) 
      .enter().append("circle") 
      .attr("r",5) 
      .attr("cy", function(d) { return d.target.y; }) 
      .attr("cx", function(d) { return d.source.x+60; }) 
      .attr("class", "linecircle") 
      .attr("fill","red"); 




     function openLink() { 
      return function(d) { 
       var url = ""; 
       if(d.slug != "") { 
        url = d.slug 
       } //else if(d.type == 2) { 
        //url = "clients/" + d.slug 
       //} else if(d.type == 3) { 
        //url = "agencies/" + d.slug 
       //} 
       window.open("//"+url) 
      } 
     } 




     var node = vis.selectAll("g.node") 
      .data(data.nodes) 
      .enter().append("svg:g") 
      .attr("class", "node") 
      .call(force.drag); 


     node.append("circle") 
      .attr("class", function(d){ return "node type"+d.type}) 
      .attr("r",function(d){if(d.entity == "description"){ return 6 } else { return 18 }}) 
      //.on("mouseover", expandNode); 
      //.style("fill", function(d) { return fill(d.type); }) 



     node.append("svg:image") 
      .attr("class", function(d){ return "circle img_"+d.name }) 
      .attr("xlink:href", function(d){ return d.img_hrefD}) 
      .attr("x", "-36px") 
      .attr("y", "-36px") 
      .attr("width", "70px") 
      .attr("height", "70px") 
      .on("click", openLink()) 
      .on("mouseover", function (d) { if(d.entity == "company") 
               { 
        d3.select(this).attr("width", "90px") 
            .attr("x", "-46px") 
            .attr("y", "-36.5px") 
            .attr("xlink:href", function(d){ return d.img_hrefL});       
               } 
       }) 
      .on("mouseout", function (d) { if(d.entity == "company") 
              { 
        d3.select(this).attr("width", "70px") 
            .attr("x", "-36px") 
            .attr("y", "-36px") 
            .attr("xlink:href", function(d){ return d.img_hrefD}); 
              } 
       });  


     node.append("text") 
      .attr("class", function(d){ return "nodetext title_"+d.name }) 
      .attr("dx", 0) 
      .attr("dy", ".35em") 
      .style("font-size","10px") 
      .attr("text-anchor", "middle") 
      .style("fill", "white") 
      .text(function(d) { if (d.entity != "description"){return d.name} }); 



     node.on("mouseover", function (d) { 
      if (d.entity == "company"){ 
       d3.select(this).select('text') 
        .transition() 
        .duration(300) 
        .text(function(d){ 
          return d.full_name; 
         }) 
        .style("font-size","15px") 

      } 
      else if(d.entity == "employee"){ 
       var asdf = d3.select(this); 
       asdf.select('text').remove(); 

       asdf.append("text") 
          .text(function(d){return d.prefix + ' ' + d.fst_name }) 
          .attr("class","nodetext") 
          .attr("dx", 0) 
          .attr("dy", ".35em") 
          .style("font-size","5px") 
          .attr("text-anchor", "middle") 
          .style("fill", "white") 
          .transition() 
          .duration(300) 
          .style("font-size","12px"); 

       asdf.append("text").text(function(d){return d.snd_name }) 
          .attr("class","nodetext") 
          .attr("transform","translate(0, 12)") 
          .attr("dx", 0) 
          .attr("dy", ".35em") 
          .style("font-size","5px") 
          .attr("text-anchor", "middle") 
          .style("fill", "white") 
          .transition() 
          .duration(300) 
          .style("font-size","12px");           
      } 
      else { 
       d3.select(this).select('text') 
        .transition() 
        .duration(300) 
        .style("font-size","15px") 
      } 

      if (d.entity == "company") { 
       d3.select(this).select('image') 
        .attr("width", "90px") 
        .attr("x", "-46px") 
        .attr("y", "-36.5px") 
        .attr("xlink:href", function (d) { 
         return d.img_hrefL 
         });    
      } 

      if (d.entity == "company") { 

       d3.select(this).select('circle') 
           .transition() 
           .duration(300) 
           .attr("r",28) 

      } 
      else if (d.entity == "employee"){ 
       d3.select(this).select('circle') 
           .transition() 
           .duration(300) 
           .attr("r",32) 
      } 
     }) 


     node.on("mouseout", function (d) { 
      if (d.entity == "company") { 
       d3.select(this).select('text') 
        .transition() 
        .duration(300) 
        .text(function(d){return d.name;}) 
        .style("font-size","10px") 
       } 
      else if(d.entity == "employee"){ 
       /////////////////////////// 
       // CHANGE 
       /////////////////////////// 

       d3.select(this).selectAll('text').remove(); 

       //d3.select(this).select('text') 
       d3.select(this).append('text') 
        .text(function(d){return d.name;}) 
        .style("font-size","14px") 
        .attr("dx", 0) 
        .attr("dy", ".35em") 
        .attr("text-anchor", "middle") 
        .style("fill", "white") 
        .attr("class","nodetext") 
        .transition() 
        .duration(300) 
        .style("font-size","10px") 

      } 
      else { 
       d3.select(this).select('text') 
        .transition() 
        .duration(300) 
        .style("font-size","10px") 
      } 


      if (d.entity == "company") { 
       d3.select(this).select('image') 
        .attr("width", "70px") 
        .attr("x", "-36px") 
        .attr("y", "-36px") 
        .attr("xlink:href", function (d) { 
        return d.img_hrefD 
       }); 
      } 

      if (d.entity == "company" || d.entity == "employee") { 

       d3.select(this).select('circle') 
           .transition() 
           .duration(300) 
           .attr("r",18) 
      } 

     }); 

     force.on("tick", function() { 
      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("transform", function(d) { return "translate(" + d.x + "," + d.y + ")"; }); 

      linkcirc.attr("cy", function(d) { return d.target.y; }) 
      .attr("cx", function(d) { return d.source.x+60; }) 
     }); 
    //}); 

Answer 1

您只需添加坐标和除以2，他们获得的中心位置：

linkcirc 
    .attr("cy", function(d) { return (d.source.y + d.target.y)/2; }) 
    .attr("cx", function(d) { return (d.source.x + d.target.x)/2; }); 

更新jsfiddle here。