Scale Controls

The six buttons appearing below the Reset Scale button all change the
scale when they are held down:

up arrow      expand the plot in the vertical direction
down arrow    contract the plot in the vertical direction

   +          expand the plot in horizontal and vertical
               directions equally
   -          contract the plot in horizontal and vertical
               directions equally

right arrow   expand the plot in the horizontal direction
left arrow    contract the plot in the horizontal direction

In addition, the data can be expanded and contracted by dragging middle
inside the plotting window.  This facility allows the reshaping of the
data in arbitrary ways.  The direction and extent of the change in
scale depends on the direction and distance the user moves the cursor.