[Loadstone] describing and storing complex points

Shawn Kirkpatrick shawn at odyssey.cm.nu
Wed Aug 8 01:18:00 BST 2007


The way you do this is with a polygon. This is a representation of a boundry 
like you discribe. Databases like postgresql can do this and indeed this is 
what the point share database does to make things like the area exporter 
work. Now getting the phone database to do this is a completely different 
story. I highly doubt it could do this and if it could I doubt it would give 
acceptable performance. It all comes back to needing a better database 
engine.

On Tue, 7 Aug 2007, Hasan Karahasan wrote:

> How could we store complex objects like borders of countries, rivers, seas,
> oceans and similar?
>
> Surely this is not interesting when walking in our home town. But I often
> use ls in exploration mode to simply explore the world.
> I think of storing such a complex object as a collection of points belonging
> together. The area within this edge points then could be recognized as
> probably being the atlantic ocean or what ever. I know that for example the
> border line of a country is never an exact straight line. So this would only
> be a approximation of the discussed area. Or think of a kind of "where am I"
> question. You need at least hundreds of points to say reliably that you are
> within the area  of a metropolitan city. If you are unlucky ls will claim
> that you are not in the city but in a suburb or village near by because its
> point is closer to you than those of your down-town. Storing areas with some
> edge coordinates would solve this with an acceptable acuracy. Of course, the
> more edge point you have the better the area is described.
>
> Hasan
>
> _______________________________________________
> Loadstone mailing list
> Loadstone at loadstone-gps.com
> http://www.loadstone-gps.com/mailman/listinfo/loadstone
>


More information about the Loadstone mailing list