re: Spatial access methods

From: John (EBo) David (ebo_at_[hidden])
Date: 2001-03-06 18:53:44

> Has anyone considered implementing a spatial access library?  

yes... Actually there was a discussion a little while back on developing
a computational geometry algorithmic library.  When I started that
discussion, or maybe I should say one of them, it was motivated by my
current research in interoperable ecological muti-scale modeling and the
need for querying spatial data.  Since I can decompose many of my
problems into classic CG representations, I figured I would start
there...

> I was 
> thinking it could including implementations for quadtrees, R-trees 
> (and variants), kd-trees, etc...  Perhaps there could be a generic 
> interface for performing spatial queries independant of the tree 
> implementation...

With spatial querying, so far I have been dealing with raster/vector
representations, bit, byte, integer, and floating point numbers.  Then
there is the issue of how to scale up and down both spatially and
temporally.  Much of what I do can be expressed in terms of:

  1) what is the spatial object (pixel, patch, or polytope) that is
closest to location XYZTE...,

  2) what are all of the objects that intersect or are inside a given
polytope,

  3) what is the distance of two given polytopes, and

  4) what are the neighbors of a given polytope

What are some of the spatial queries that you need?

  EBo -- ebo_at_[hidden]