-You can measure distances and forces directly in the plot. Just issue
-the command ``distance``. You will be asked to click two points.
-When you click a point, a blue dot should appear. When you click the
-second point, the distances (in nanometers and piconewtons) will
-appear on the command line. You can use ``delta`` if you prefer,
-which gives meaningful values for every kind of graph (not only force
-curves). If you want to know the coordinates of a single point, use
-``point``.