    left_chart_scene = vtkContextScene()
    left_chart_actor = vtkContextActor()

    left_chart_scene.AddItem(left_chart)
    left_chart_actor.SetScene(left_chart_scene)

--
    right_chart_scene = vtkContextScene()
    right_chart_actor = vtkContextActor()

    right_chart_scene.AddItem(right_chart)
    right_chart_actor.SetScene(right_chart_scene)

