[mapserver-users] WFS Filter encoding . . . Anyone know what the Units list for DWithin that MapServer honors?

[Yewondwossen Assefa]

On 11/07/2010 6:02 PM, Blammo wrote:
> More info,
>
> Using this service call:
>
> https://www.sharedgeo.org/MNGEO-ro/public/ows?SERVICE=wfs&VERSION=1.1.0&REQUEST=getFeature&TYPENAME=layer_3&FILTER=%3CFilter%3E%3CDWithin%3E%3CPropertyName%3EGeometry%3C/PropertyName%3E%3Cgml:Point%3E%3Cgml:coordinates%3E-93.093,44.955%3C/gml:coordinates%3E%3C/gml:Point%3E%3CDistance%20units=%27f%27%3E0.0438%3C/Distance%3E%3C/DWithin%3E%3C/Filter%3E 
>
>
> I tried, FT, FEET, Ft, ft, Feet and f, (this last, the "f" is the only 
> thing that changed the results, but it only increased the return from 
> three to six points):
>
> I used the same unit distance of 0.0438, which the majority of time 
> returns three points. These points in ground units are actually within 
> ~2360ft of each other.  I have no idea how the 0.0438 number relates 
> to that.  Is it possibly related to the LAT/LON coordinate system?
>
> This is working enough for me to get through my current stage of 
> development, I'm just trying to get a handle on how the filter units 
> are supposed to relate to the map units.  Maybe DWithin has a PROJ 
> option or something??
>

When the units in unrecognized (like "f" in this case), It should be 
ignored the and distance is assumed to be the same units as the gml 
element that was part of the query.  You can add a projection to the gml 
element using the srsrName element.

best regards,


-- 
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Assefa Yewondwossen
Software Analyst

Email: yassefa at dmsolutions.ca
http://www.dmsolutions.ca/

Phone: (613) 565-5056 (ext 14)
Fax:   (613) 565-0925
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