I realise this post is now a few months old, but for the benefit of anyone finding this on a search engine...

Building on zentara's suggestion to use the Tk::Canvas widget, it is worth pointing out that Tk::PlotDataser is derived from the Tk::Canvas class. Therefore any methods you can call on Tk::Canvas can also be called on Tk::PlotDataset. Rather than reimplementing a graphing module in a Tk::Canvas, use Tk::PlotDataset and draw on your own labels. Add the code that draws the labels to the -redraw subroutine so they are not lost when zooming or resizing the graph.

Tim (Senior Engineer @ ITDev)