Hello,
I am getting different results from a DWITHIN query from WMS and WFS.
Doing this:
results in KS, SD, and NE.
On the other hand, if I add DWITHIN(the_geom,POINT(-99.22
41.56),3,meters) in the OpenLayers map preview for topp:states, I get
CO,KS,IA,SD,NE.
In the application that I am doing, I am using a layer that uses
EPSG:41001 projection and is in meters, but I am encountering
conflicting results similar to above.
Am I doing something wrong?
Thanks.
Mario,
Mario Basa ha scritto:
Hello,
I am getting different results from a DWITHIN query from WMS and WFS.
Doing this:
results in KS, SD, and NE.
DWithin works only in projected systems, we don't have the math necessary to locate the geometries within a certain metric distance
from a generic geometry expressed in geographic coordinates.
On the other hand, if I add DWITHIN(the_geom,POINT(-99.22
41.56),3,meters) in the OpenLayers map preview for topp:states, I get
CO,KS,IA,SD,NE.
The shapefile renderer is optimized for speed, this means in particular
it's skipping all secondary filters. Basically it's treating the
above filter as a bbox one.
Can you open a bug report for this?
In the application that I am doing, I am using a layer that uses
EPSG:41001 projection and is in meters, but I am encountering
conflicting results similar to above.Am I doing something wrong?
You're using shapefiles 
The above should not happen if you use a database.
Cheers
Andrea
--
Andrea Aime
OpenGeo - http://opengeo.org
Expert service straight from the developers.
Thanks Andrea,
I just tried placing my layers into PostGIS and I am getting
compatible results now from both wms and wfs.
I am curious though how WMS handles filters with PostGIS; does it get
the data that falls in the bbox first and then do a dwithin with the
selected data, or does it execute both bbox and dwithin queries in one
pass? I am really hoping it is the latter.
I am a bit new here, so how do I make a bug report. If you can direct
me to link on how to do it, I will file the bug below.
Thanks again.
Mario.
On Fri, Jun 12, 2009 at 3:27 PM, Andrea Aime<aaime@anonymised.com> wrote:
Mario Basa ha scritto:
Hello,
I am getting different results from a DWITHIN query from WMS and WFS.
Doing this:
results in KS, SD, and NE.
DWithin works only in projected systems, we don't have the math necessary to
locate the geometries within a certain metric distance
from a generic geometry expressed in geographic coordinates.On the other hand, if I add DWITHIN(the_geom,POINT(-99.22
41.56),3,meters) in the OpenLayers map preview for topp:states, I get
CO,KS,IA,SD,NE.The shapefile renderer is optimized for speed, this means in particular
it's skipping all secondary filters. Basically it's treating the
above filter as a bbox one.Can you open a bug report for this?
In the application that I am doing, I am using a layer that uses
EPSG:41001 projection and is in meters, but I am encountering
conflicting results similar to above.Am I doing something wrong?
You're using shapefiles
The above should not happen if you use a database.Cheers
Andrea--
Andrea Aime
OpenGeo - http://opengeo.org
Expert service straight from the developers.
Mario Basa ha scritto:
Thanks Andrea,
I just tried placing my layers into PostGIS and I am getting
compatible results now from both wms and wfs.I am curious though how WMS handles filters with PostGIS; does it get
the data that falls in the bbox first and then do a dwithin with the
selected data, or does it execute both bbox and dwithin queries in one
pass? I am really hoping it is the latter.
As far as I know, the latter.
I am a bit new here, so how do I make a bug report. If you can direct
me to link on how to do it, I will file the bug below.
1) jira.codehaus.org
2) register
3) submit a report on GeoServer
For the general guidelines on who to submit a bug, we don't
have anything written down for GeoServer, but this is general
enough to apply:
http://www.chiark.greenend.org.uk/~sgtatham/bugs.html
Cheers
Andrea
--
Andrea Aime
OpenGeo - http://opengeo.org
Expert service straight from the developers.