r-trees
Eric Holton
Thanks
Eric
Julian M Bucknall
Eric Holton wrote:
> Has anyone implemented r-tree (r*-tree) ? if not how B+-tree?
I don't know of any implementations of r-trees in Delphi. As for
B+-tree, you'll have to define what you mean (I know of two
contradictory definitions - the world of B-trees tends to propagate
dissimilar definitions) you might find something out there. The book
File Structures by Folk and Zoellick describes B-trees
http://www.amazon.com/exec/obidos/ASIN/0201874016
--
Cheers, Julian
-----------------------------------------------------------
Julian M Bucknall
nospam...@turbopower.com (delete nospam)
TurboPower Software Company - www.turbopower.com
Personal - www.home.turbopower.com/~julianb
-----------------------------------------------------------
Eric Holton
Does FlashFiler allow user defined indexes (ie could I create r-tree index
to access my data?)
Eric
Julian M Bucknall wrote in message <36431F7D...@turbopower.com>...
clayton collie
Eric Holton wrote in message <71v3si$ir...@forums.borland.com>...
>Has anyone implemented r-tree (r*-tree) ? if not how B+-tree?
>
> Eric
>
for us newbies out there, what is a r-tree ?
clayton collie
Eric Holton
with different rules of Node Spliting.
Example
[(1,1),(1,1)] [(2,2),(1,1)] [(2,2),(2,2)] -- Leaves
[(1,2),(1,1)] [(2,2),(1,2)] -- Nodes
[(1,2),(1,2)] -- Root
The stuff in () are the bounding box for the data.
It is used alot in Maping Applications
Eric
clayton collie wrote in message <71vd06$ip...@forums.borland.com>...
Julian M Bucknall
clayton collie wrote:
> for us newbies out there, what is a r-tree ?
It's a way of indexing spatial data or multi-dimensional data and then
doing queries on those indexes. r-trees arise in applications like
cartography, CAD, robotics, computer vision and so on. Queries you do
are typically range queries: given a rectangle, retrieve all objects
that intersect it; or point queries, given a point, retrieve all objects
that contain it.
The original paper is by A. Guttman, "R-trees: a dynamic index structure
for spatial searching" Proc. ACM SIGMOD.
Julian M Bucknall
Eric Holton wrote:
> B-Tree would work,
I dare say that Torry's has something although I've never looked
(http://www.torry.ru). I've started writing one for my EZDSL library, but
haven't got very far yet. Real life keeps intruding. Our B-Tree Filer and
FlashFiler come with full source code, the one in BTF being easier to extract.
> Does FlashFiler allow user defined indexes (ie could I create r-tree index
> to access my data?)
Yes.
David Berneda
I did T-Tree... <g>
Well, it's not an indexing algorithm, but a
generic "any-tree" drawing component.
Regards
David Berneda
http://www.teemach.com
Kammann, Martin
> I did T-Tree... <g>
I love Tee Tree, it's oil helps against virtual anything, even sleeping
feet.
<g>
- Martin
James Higgins
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James Higgins
On Fri, 27 Nov 1998 21:19:38 -0800, Richard Hughes
<rhug...@mindspring.com> wrote:
><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
><HTML>
>Rod Stephens in his book <I>Ready-to-Run Delphi 3.0 Algorithms </I>devotes
>3 chapters to trees all with code included. B+ trees are covered
>but I don't remember seeing a reference to r-trees.
><P>Carey Rossiter
><P>Eric Holton wrote:
><BLOCKQUOTE TYPE=CITE>Has anyone implemented r-tree (r*-tree) ? if not
>how B+-tree?
><P>Thanks
><BR> Eric</BLOCKQUOTE>
></HTML>
>