anchor.diff:  function change(data) {
   
     function show_percent(d) {
  +    if (animating) return;
       svg.select(".percent").select("text")
         .text(percent(d));
   
  
positive.code:     .style("text-anchor", "middle")
      .style("font-size", "1.9em");
  
  
  
  
  var color = d3.scale.category20();
  
  var pie = d3.layout.pie()
  
negative.code:       var interpolate = d3.interpolate(this._current, d);
        this._current = interpolate(0);
        return function(t) { return arc(interpolate(t)); };
      })
      .each('start',function(d) { animating = true; })
      .each('end',  function(d) { animating = false; });
  
    slice.exit()
      .remove();
  