d3-filter.js

var markGroup = dataGroup.selectAll(".mark")
  .data(flatData).enter()
  .append("svg:g")
  .attr("class","mark");

markGroup.append("svg:rect").
  attr("x", function (d,i) { return x(i); }).
  attr("y", 0).
  attr("class", targetStyle(this.kind)).
  attr("width", widthFunc(this)).
  attr("height", this.height);

markGroup.append("svg:line").
  filter(function(d, i) { return (targetStyle())(d) != "targetHit"; }).
  attr("x1", function (d,i) { console.log("idx "+i); return barXScale(i); }).
  attr("y1", 0).
  attr("x2", function (d,i) { return barXScale(i+1)-1; }).
  attr("y2", this.height).
  attr("stroke-dasharray", "2 2");