如何使用d3将箭头添加到扩展程序图表中的标记

Question

Fiddle Example

我想知道如何在子弹图中为符号标记添加箭头标记，以明确其含义，如下所示：

我已尝试将此代码块添加到项目符号功能中，但无处可见：

  marker.enter().append("line")
    .attr("class", "marker")
    .attr("marker-start","url(#avg)")
    .attr("x1", x0)
    .attr("x2", x0)
    .attr("y1", height / 6)
    .attr("y2", height * 5 / 6)

  g.append("svg:defs")
   .append("svg:marker")
   .attr("id", "avg")
   .attr("viewBox", "0 5 10 10")
   .attr("refX", 340)
   .attr("refY", 1)
   .attr("markerWidth", 6)
   .attr("markerHeight", 6)
   .attr("orient", "auto")
   .append("svg:path")
   .attr("d", "M0,-5L10,0L0,5");

有人可以告诉我如何添加箭头标记吗？

以下是代码：

(function() {

// Chart design based on the recommendations of Stephen Few. Implementation
// based on the work of Clint Ivy, Jamie Love, and Jason Davies.
// http://projects.instantcognition.com/protovis/bulletchart/
d3.bullet = function() {
  var orient = "left", // TODO top & bottom
      reverse = false,
      duration = 0,
      ranges = bulletRanges,
      markers = bulletMarkers,
      measures = bulletMeasures,
      width = 380,
      height =100,
      tickFormat = null;

  // For each small multiple…
  function bullet(g) {
    g.each(function(d, i) {
      var rangez = ranges.call(this, d, i).slice().sort(d3.descending),
          markerz = markers.call(this, d, i).slice().sort(d3.descending),
          measurez = measures.call(this, d, i).slice().sort(d3.descending),
          g = d3.select(this);

      // Compute the new x-scale.
      var x1 = d3.scale.linear()
          .domain([0, Math.max(rangez[0], markerz[0], measurez[0])])
          .range(reverse ? [width, 0] : [0, width]);

      // Retrieve the old x-scale, if this is an update.
      var x0 = this.__chart__ || d3.scale.linear()
          .domain([0, Infinity])
          .range(x1.range());

      // Stash the new scale.
      this.__chart__ = x1;

      // Derive width-scales from the x-scales.
      var w0 = bulletWidth(x0),
          w1 = bulletWidth(x1);

      // Update the range rects.
      var range = g.selectAll("rect.range")
          .data(rangez).enter()

      var range2 = range.append("rect")
          .attr("class", function(d, i) { return "range s" + i; })
          .attr("width", w0)
          .attr("height", height)
          .attr("x", reverse ? x0 : 0)
        .transition()
          .duration(duration)
          .attr("width", w1)
          .attr("x", reverse ? x1 : 0)
        .transition()
          .duration(duration)
          .attr("x", reverse ? x1 : 0)
          .attr("width", w1)
          .attr("height", height);

        range.append("text").text(function(d,k){
         console.log(k)   
        })
      .attr("x",w1)
      .attr("y",height * 2)
      .attr("class","3232")


      // Update the measure rects.
      var measure = g.selectAll("rect.measure")
          .data(measurez).enter()

          measure.append("rect")
          .attr("class", function(d, i) { return "measure s" + i; })
          .attr("width", w0)
          .attr("height", height / 3)
          .attr("x", reverse ? x0 : 0)
          .attr("y", height / 3)
          .attr("marker-end","url(#b_1)")
        .transition()
          .duration(duration)
          .attr("width", w1)
          .attr("x", reverse ? x1 : 0)
          .transition()
          .duration(duration)
          .attr("width", w1)
          .attr("height", height / 3)
          .attr("x", reverse ? x1 : 0)
          .attr("y", height / 3);

      // Update the marker lines.
      var marker = g.selectAll("line.marker")
          .data(markerz);

      marker.enter().append("line")
          .attr("class", "marker")
          .attr("marker-start","url(#avg)")
          .attr("x1", x0)
          .attr("x2", x0)
          .attr("y1", height / 6)
          .attr("y2", height * 5 / 6)
        .transition()
          .duration(duration)
          .attr("x1", x1)
          .attr("x2", x1);

      marker.transition()
          .duration(duration)
          .attr("x1", x1)
          .attr("x2", x1)
          .attr("y1", height / 6)
          .attr("y2", height * 5 / 6);

      // Compute the tick format.
      var format = tickFormat || x1.tickFormat(8);

      // Update the tick groups.
      var tick = g.selectAll("g.tick")
          .data(x1.ticks(8), function(d) {
            return this.textContent || format(d);
          });

      // Initialize the ticks with the old scale, x0.
      var tickEnter = tick.enter().append("g")
          .attr("class", "tick")
          .attr("transform", bulletTranslate(x0))
          .style("opacity", 1e-6);

      tickEnter.append("line")
          .attr("y1", height)
          .attr("y2", height * 7 / 6);

      tickEnter.append("text")
          .attr("text-anchor", "middle")
          .attr("dy", "1em")
          .attr("y", height * 7 / 6)
          .text(format);

      // Transition the entering ticks to the new scale, x1.
      tickEnter.transition()
          .duration(duration)
          .attr("transform", bulletTranslate(x1))
          .style("opacity", 1);

      // Transition the updating ticks to the new scale, x1.
      var tickUpdate = tick.transition()
          .duration(duration)
          .attr("transform", bulletTranslate(x1))
          .style("opacity", 1);

      tickUpdate.select("line")
          .attr("y1", height)
          .attr("y2", height * 7 / 6);

      tickUpdate.select("text")
          .attr("y", height * 7 / 6);

      // Transition the exiting ticks to the new scale, x1.
      tick.exit().transition()
          .duration(duration)
          .attr("transform", bulletTranslate(x1))
          .style("opacity", 1e-6)
          .remove();

      g.append("svg:defs")
       .append("svg:marker")
       .attr("id", "avg")
       .attr("viewBox", "0 5 10 10")
       .attr("refX", 340)
       .attr("refY", 1)
       .attr("markerWidth", 6)
       .attr("markerHeight", 6)
       .attr("orient", "auto")
       .append("svg:path")
       .attr("d", "M0,-5L10,0L0,5");
    });
    d3.timer.flush();
  }

  // left, right, top, bottom
  bullet.orient = function(x) {
    if (!arguments.length) return orient;
    orient = x;
    reverse = orient == "right" || orient == "bottom";
    return bullet;
  };

  // ranges (bad, satisfactory, good)
  bullet.ranges = function(x) {
    if (!arguments.length) return ranges;
    ranges = x;
    return bullet;
  };

  // markers (previous, goal)
  bullet.markers = function(x) {
    if (!arguments.length) return markers;
    markers = x;
    return bullet;
  };

  // measures (actual, forecast)
  bullet.measures = function(x) {
    if (!arguments.length) return measures;
    measures = x;
    return bullet;
  };

  bullet.width = function(x) {
    if (!arguments.length) return width;
    width = x;
    return bullet;
  };

  bullet.height = function(x) {
    if (!arguments.length) return height;
    height = x;
    return bullet;
  };

  bullet.tickFormat = function(x) {
    if (!arguments.length) return tickFormat;
    tickFormat = x;
    return bullet;
  };

  bullet.duration = function(x) {
    if (!arguments.length) return duration;
    duration = x;
    return bullet;
  };

  return bullet;
};