 
   hoverRefresh: =>
     return if !@options.hoverId?
-    return if @data.length == 0
+    return if !@data[0]?
 
     x = @options.scales.x.invert(d3.mouse(@svgHoverArea.node())[0] - @margins.left)
     i = @lookupIndexFromX x

    @loadData data


  loadData: (data) =>
    return if _.isEqual data, @data




  reveal: =>
    return @hide() if !@data[0]?

    @recalc()

    @svgLine
