         mark.element.style.left = (scaledMin) + "px"
         mark.save(scaledMin, scaledMax)
 
-    # draw scales
+    @drawYTickMarks([0..20], [0..@canvas.height], 1, 2)
+
     tickMinorInterval = 1
     tickMajorInterval = 4
     tickMinorLength = 5


    # normalize data
    @data.y = @normalize(@data.y)

  enableMarking: ->
    @marks = new Marks
    window.marks = @marks
    @canvas.addEventListener 'mousedown', (e) => @addMarkToGraph(e)
    @canvas.addEventListener 'touchstart', (e) => @addMarkToGraph(e)

  plotPoints: (xMin = @smallestX, xMax = @largestX, yMin = @smallestY, yMax = @largestY) ->
    @xMin = xMin

    @scale = (@largestX - @smallestX) / (@xMax - @xMin)

  normalize: (values) ->
    norm = []
    for value, idx in [values...]
      norm[idx] =  ( parseFloat(value) - Math.min(values...) ) / ( Math.max(values...) - Math.min(values...) )
    return norm

  zoomInTo: (wMin, wMax) ->
    [cMin, cMax] = [@xMin, @xMax]
