       # update the scaling function
       #
       @y = d3.scale.linear().
-        domain([0, max_height * 1.2]).
-        range([0, @height * .9])
+        domain([0, max_height * 1.25]).
+        range([0, @height * .90])
 
       # refresh the unit squares
       #

    siblings: =>
      items = _.groupBy(@module.nodes.models, (node) -> node.get('column'))
      items[@get 'column']
    
    label: => @get('label') || @get('id')


  Link: class extends Backbone.Model
    initialize: =>

    #
    y_offset: =>
      offset = 0
      margin = 50
      for n in @siblings()
        break if n == this
        offset += n.value() + margin
