Re: [sqlite] Sqlite RTree nearest neighbour

2014-08-23 Thread skywind mailing lists
Hi Clemens, thanks for the link! Regards, Hartwig Am 22.08.2014 um 22:26 schrieb Clemens Ladisch : > skywind mailing lists wrote: >> I hoped that somebody already tried to implement a nearest neighbor >> algorithm. > > Typically, objects are not axis-aligned rectangles, and the R-tree is > jus

Re: [sqlite] Sqlite RTree nearest neighbour

2014-08-22 Thread Clemens Ladisch
skywind mailing lists wrote: > I hoped that somebody already tried to implement a nearest neighbor > algorithm. Typically, objects are not axis-aligned rectangles, and the R-tree is just an index based on the bounding boxes. Computing the (nearest) distance would require the actual geometries. >

Re: [sqlite] Sqlite RTree nearest neighbour

2014-08-22 Thread skywind mailing lists
Hello, I hoped that somebody already tried to implement a nearest neighbor algorithm. Is the format of the shadow tables somewhere documented or do I have to analyze the source code? Regards, Hartwig Am 22.08.2014 um 02:58 schrieb Richard Hipp : > On Thu, Aug 21, 2014 at 8:54 PM, Peter Aronso

Re: [sqlite] Sqlite RTree nearest neighbour

2014-08-21 Thread Richard Hipp
On Thu, Aug 21, 2014 at 8:54 PM, Peter Aronson wrote: > 1. You would need to access SQLite's R-Tree "shadow" tables > (xx_node, xx_parent, xx_rowid) directly in to perform the traversals > required by all of the algorithms -- I don't know if this is officially > supported by SQLite's deve

Re: [sqlite] Sqlite RTree nearest neighbour

2014-08-21 Thread Peter Aronson
According to R-Trees: Theory and Applications by Yannis Manolopoulos, Alexandros Nanopoulos, Apostolos N. Papadopoulos and Yannis Theodoridis, there are a number of algorithms for efficiently determining the nearest neighbor(s) using an R-Tree (an internet search on the two terms will pull up se

Re: [sqlite] Sqlite RTree nearest neighbour

2014-08-21 Thread Carlos Ferreira
... -Original Message- From: sqlite-users-boun...@sqlite.org [mailto:sqlite-users-boun...@sqlite.org] On Behalf Of Simon Slavin Sent: quinta-feira, 21 de Agosto de 2014 23:09 To: General Discussion of SQLite Database Subject: Re: [sqlite] Sqlite RTree nearest neighbour On 21 Aug 2014, at 10

Re: [sqlite] Sqlite RTree nearest neighbour

2014-08-21 Thread Simon Slavin
On 21 Aug 2014, at 10:32pm, skywind mailing lists wrote: > does anybody have any experience with implementing a nearest neighbor search > using SQLite's RTree functionality? Is a nearest neighbor search possible? How much have you read ? Are you familiar with SpaciaLite ? Have you tried im

[sqlite] Sqlite RTree nearest neighbour

2014-08-21 Thread skywind mailing lists
Hello, does anybody have any experience with implementing a nearest neighbor search using SQLite's RTree functionality? Is a nearest neighbor search possible? Regards, Hartwig ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:80