     (t) ->
       b = i(t)
       return @arc b
-
   removePieTween: (d, i) ->
     `var i`
     that = this

      # Move all calculations into the each function.
      # Position values are stored in the data object 
      # so can be accessed later when drawing the line

      ### calculate the position of the center marker ###

      a = (d.startAngle + d.endAngle) / 2
      #trig functions adjusted to use the angle relative
      #to the "12 o'clock" vector:
      #console.log 'ts: a', a
      d.cx = Math.sin(a) * (radius - 75)
      d.cy = -Math.cos(a) * (radius - 75)

      ### calculate the default position for the label,
         so that the middle of the label is centered in the arc
      ###

      bbox = @getBBox()
      #bbox.width and bbox.height will 
      #describe the size of the label text

      ### check whether the default position 
         overlaps any other labels
      ###
      conflicts = []
      labelLayout.visit (node, x1, y1, x2, y2) ->
        #recurse down the tree, adding any overlapping 
