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From Chris Male <gento...@gmail.com>
Subject Re: Rethinking spatial implementation
Date Mon, 08 Nov 2010 10:40:52 GMT
Hi,

I'll jump in and give my opinion:

Can you clarify what you mean with "the Sinusoidal projection is broken"?
>

Inside Spatial Lucene's Cartesian codebase is an implementation of
Sinusoidal projection.  Grant discovered while working on improving the
testing coverage of the code that the implementation doesn't actually match
the formula specified on Wikipedia.  When we tried to change it, many tests
broke since the overall logic somehow depends on this broken implementation.


>
> Would it be possible to use a LGPL library like the Java Topology Suite
> (JTS: http://www.vividsolutions.com/jts/JTSHome.htm)?
>

This is something we've talked about using.  I think it would be nice to
offload some of the geographic-specific from Lucene.  So using another
library would be good.  At the same time it limits our options for
optimizations and the like.  I'm certainly looking into it though.

Thanks,
Chris


>
> Neo4j is using JTS for creating a spatial index (code is here:
> https://github.com/neo4j/neo4j-spatial)...
>
> (I've just seen that JTS has some index creation classes, but I'm not at
> all familiar with them)
>
> Christopher
>
>
> On Mon, Nov 8, 2010 at 1:10 AM, Grant Ingersoll <gsingers@apache.org>wrote:
>
>>
>> On Nov 6, 2010, at 5:23 PM, Christopher Schmidt wrote:
>>
>> > Hi Ryan, thx for your answer.
>> >
>> > You mean there is room for improvement and volunteers?
>>
>> We've been looking at replacing it with the Military Grid system.  The
>> primary issue with the current is that the Sinusoidal projection is broken
>> which then breaks almost all the tests.  I worked on it for a while trying
>> to straighten it out, but gave up and now think it is easier to implement
>> clean.  I definitely would like to see a tier/grid implementation.
>>
>>
>> >
>> > On Friday, November 5, 2010, Ryan McKinley <ryantxu@gmail.com> wrote:
>> >> Hi Christopher -
>> >>
>> >> I do not believe there is any active work on this.  From what I
>> >> understand, the Tier implementation works OK within some constraints,
>> >> but we could not get it to pass more robust testing that the other
>> >> methods were using.
>> >>
>> >> However, LatLonType and GeoHashField are well tested and work well --
>> >> the Tier type may have better performance when your index is really
>> >> large, but no active developers understand it and no-one has stepped
>> >> up to figure it out.
>> >>
>> >> ryan
>> >>
>> >>
>> >> On Wed, Nov 3, 2010 at 3:16 PM, Christopher Schmidt
>> >> <fakod666@googlemail.com> wrote:
>> >>> Hi all,
>> >>> I saw a mail thread "Rethinking Cartesian Tiers implementation"
>> (here).
>> >>> Is there any work in progress regarding this? If yes, is the current
>> >>> implementation deprecated or do you plan some enhancements (other
>> >>> projections or spatial indexes) ?
>> >>> I am asking because I want to use Lucene's spatial indexing in a
>> production
>> >>> system...
>> >>>
>> >>> --
>> >>> Christopher
>> >>> twitter: @fakod
>> >>> blog: http://blog.fakod.eu
>> >>>
>> >>
>> >> ---------------------------------------------------------------------
>> >> To unsubscribe, e-mail: dev-unsubscribe@lucene.apache.org
>> >> For additional commands, e-mail: dev-help@lucene.apache.org
>> >>
>> >>
>> >
>> > --
>> > Christopher
>> > twitter: @fakod
>> > blog: http://blog.fakod.eu
>> >
>> > ---------------------------------------------------------------------
>> > To unsubscribe, e-mail: dev-unsubscribe@lucene.apache.org
>> > For additional commands, e-mail: dev-help@lucene.apache.org
>> >
>>
>> --------------------------
>> Grant Ingersoll
>> http://www.lucidimagination.com/
>>
>> Search the Lucene ecosystem docs using Solr/Lucene:
>> http://www.lucidimagination.com/search
>>
>>
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: dev-unsubscribe@lucene.apache.org
>> For additional commands, e-mail: dev-help@lucene.apache.org
>>
>>
>
>
> --
> Christopher
> twitter: @fakod
> blog: http://blog.fakod.eu
>
>


-- 
Chris Male | Software Developer | JTeam BV.| www.jteam.nl

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