Boost logo

Geometry :

Subject: Re: [geometry] R-Tree Nearest Neighbors Unique Member From Group
From: jpb (jberg_at_[hidden])
Date: 2018-05-16 18:33:39

Hi Adam,

Thanks for taking the time to think about this and replying with your
thoughts. I appreciate it.

So for this application each of the N-groups are all pretty localized and N
is a large number, so I think I could keep each group in a group-r-tree and
then keep each group-r-tree in an overarching-r-tree (with things like
indexable and compariable_distance for a group-r-tree and a point overloaded
to give the distance between the closest object in the r-tree to the point).
If I did that, I could run a nearest neighbor search on the
overarching-r-tree and get the k closest group-r-tree's, but then in order
to get the objects in each group-r-tree, I'd have to run another nearest
neighbor search on the group-r-tree. Is there a good way around that
repeated computation?

If that doesn't work, I might just put all of the objects in a single r-tree
and get all or the objects withing a certain range (using something like the
intersects query) and then process those items to get what I want, and then
just live with the fact that fewer than k groups might intersect a range, so
it would be a find the nearest k-or-less neighbors with at most one in each
group query.

Thanks again.

Sent from:

Geometry list run by mateusz at