1

I'm using the semi-new Devexpress Map Control to draw polygons (that I call areas). I need to calculate the area of a polygon just by giving the points of that area.

My problem is Devexpress doesn't have a method to do that yet, so, I want to know if anybody know how can I calculate that are, giving latitude and logitude of some points.

I found some example explaining it with small coordinates like 1.1, 2.2... But with real world coordinates we have in some cases 39.012412312 and -08.12412312.

Thanks in advance

user1728596
  • 41
  • 1
  • 5
  • 4
    possible duplicate of [Is there any algorithm for calculating area of a shape given co-ordinates that define the shape?](http://stackoverflow.com/questions/2432428/is-there-any-algorithm-for-calculating-area-of-a-shape-given-co-ordinates-that-d) – Ahmed KRAIEM Aug 29 '13 at 15:44
  • 1
    Are you trying to convert from Lat/Lng to UTM coordinates first? If so, what formula are you using? Also, what is the max-size you think it could possibly cover? More than a few square miles will have some consistency issues. – moron4hire Aug 29 '13 at 15:56
  • I don't know the exactly max-size... I found one algorithm to do it with triangles....the problem was that I was using ponint #1 as the master and making triangles with all the others consecutive points. But when the poligon was like a banana, the master point was in one tip and the other point on the other tip, it calculates the out area. – user1728596 Aug 29 '13 at 16:02
  • 1
    "Like a banana" is called a concave polygon. I like to think of it as "it is shaped like a cave". Non-concave polygons are called convex. Unfortunately, dealing with concave polygons is quite difficult. Almost all algorithms that deal with them deal with first splitting them to a list of convex polygons. This itself is a very costly operation, say nothing about the subsequent ops. – moron4hire Aug 29 '13 at 16:06
  • Yes, I can understand that, it's been "very costly" to my brain to think in a solution... Is there a way to do that? Or an ebook or something I can read to understand how can I build an algorithm? And as you asked, yes, I have a way to convert lat/lng to UTM. – user1728596 Aug 29 '13 at 16:19

0 Answers0