anchor.diff:  
       // If user double click, reinitialize the chart
       svg.on("dblclick",function(){
  -      x.domain(d3.extent(data, function(d) { return d.sentence_index; }))
  +      x.domain(d3.extent(word_count_data, function(d) { return d.sentence_index; }))
         xAxis.transition().call(d3.axisBottom(x))
         line
           .select('.line')
  
positive.code:       .append("g")
          .attr("transform", "translate(" + margin.left + "," + margin.top + ")");
  
      <%= analysis.words_per_sentence %>.forEach(function (data) {
        console.log(data);
      });
  
      //Read the data
      data = word_count_data;
  
      console.log(data);
  
      // Add X axis --> it is a date format
      var x = d3.scaleLinear()
        .domain(d3.extent(data, function(d) { return d.sentence_index; }))
        .range([ 0, width ]);
      xAxis = svg.append("g")
        .attr("transform", "translate(0," + height + ")")
  
negative.code: 
      // Add Y axis
      var y = d3.scaleLinear()
        .domain([0, d3.max(word_count_data, function(d) { return +d.value; })])
        .range([ height, 0 ]);
      yAxis = svg.append("g")
        .call(d3.axisLeft(y));
  