


This is a
standard xy scatter chart. It has 2 data series plotted as
markers only. The VBA code will then calculate the bounding area
and output the necessary X and Y values in order to plot the
encapsulating lines.




The technique for determining
the bounding line is one known as 'gift wrapping'.
The lowest x value point is
chosen as the starting point and the each other point is checked
to find the one that causes the smallest change in angle.



The
example workbook contains the relevant class code to produce
a set of bounding x and y values.
The animation property is purely for fun and demonstration.
There is also a property to
to control how tight the bounding line fits the points.
The example above is not a tight fit as the bounding lines are
not touching the points.
