# Hi Yall - Given a scatter plot of say 5000 points ....

• 02-11-2002
Anonymous
Hi Yall - Given a scatter plot of say 5000 points how can I construct an enclosing polygon ?
(Not strictly a MapPoint problem.)
Thanks in anticipation Dave (UK)
• 02-11-2002
Walt Cygan
Wow! Throw out a hard one for a Monday morning, why don't you?

If I understand your question properly you want a polygon that encloses all 5000 points. The problem to my thinking is that there are a lot of qualifying polygon, depending on how you define what you want. You may have to submit another question with a more refined formulation of what you are looking for.

For example, the easiest polygon to create would be a spherical rectangle where the sides were defined by minimum and maximum values of both latitude and longitude. I'll wager that is not what you want, though. The problem is how far down into the spread of points do you go to create the polygon. Should the polygon be the smallest possible polygon where all angles are concave?

Even if I know the rules, I may not be able to formulate a useful solution. This would seem to be a reasonably complex problem in spherical geometry, for which I am almost certainly not your best source. You may want to try the MapPoint newsgroup at "microsoft.public.mappoint" to get more brains applied to the problem.

- Walt Cygan