         .select('text')
         .text((d) -> "#{d.get 'key'} #{parseInt d.total_value()} PJ")
 
-      # we need to track the offset for every sector
+      # let's track the vertical offset for every sector
       offsets = {}
-      for sector in @sector_list.pluck('key')
-        offsets[sector] = 0
-
+      offsets[sector] = 0 for sector in @sector_list.pluck('key')
+
+      # Update the rectangles
+      #
       @svg.selectAll(".carrier")
         .data(@node_list.models, (d) -> d.key())
         .transition().duration(500)

          label: s.get('label')
          color: s.get('color')
          view: this
      sectors  = _.uniq sectors
      carriers = _.uniq(carriers, false, (c) -> c.label)

      for sector in sectors
        @sector_list.add
          key: sector
          view: this
      for carrier in carriers
        @carrier_list.add
          key: carrier.label

D3.mekko =
  # This represents a carrier within a sector, ie a chart rectangle
  #
  Node: class extends Backbone.Model
    initialize: =>
      @view = @get 'view'
