[geos-devel] supporting filters

[Mateusz Loskot]

Mateusz Loskot wrote:
> Kralidis,Tom [Burlington] wrote:
>>> Tom,
>>>
>>> I'm also interested in some info about internals of DWithin 
>>> and Beyond operations.
>>> These both operations are supported by FDO 
>>> (http://fdo.osgeo.org) but unfortunately I've not found much 
>>> information about their specification.
>> True.  The only info I found was from FES 1.0.0, section 8.2:
>>
>> "The spatial operators DWithin and Beyond test whether the value of a
>> geometric property is within or beyond a specified distance of the
>> specified literal geometric value."
>>
>> So both DWithin and Beyond take as inputs a geometry and distance value.
> 
> Right.
> 
> But I'd like to get more details, some math declarations or geometries
> examples.
> I asked on the FDO list about them:
> 
> http://lists.osgeo.org/pipermail/fdo-internals/2007-May/001072.html

Tom,

It seems these new spatial operators are based on Oracle features.
Here is longer explanation posted as a reply to my question, on the FDO
list:

http://lists.osgeo.org/pipermail/fdo-internals/2007-May/001074.html

Hope that helps.

Cheers
-- 
Mateusz Loskot
http://mateusz.loskot.net