Re: [udig-users] shape file representation

[Frank Gasdorf <fgdrf@xxxxxxxxxxxxxxxxxxxxx>]

Hmm, I guess you can define a PointSymolizers with a "different"
geometry object coming from a geometry function such as centriod:

<PointSymbolizer>
  <Geometry>
     <ogc:Function name="centroid">
        <ogc:PropertyName>the_geom</ogc:PropertyName>
     </ogc:Function>
  </Geometry>
  <Graphic>
   [...]
  </Graphic>
</PointSymbolizer>
<PolygonSymbolizer>
  [...]
</PolygonSymbolizer>

Cheers
Frank

2012/5/6 andrea antonello <andrea.antonello@xxxxxxxxx>:
>> Another technique would be to do this with a style.
>>
>> If you use a point symboliser it will draw the centred of each polygon. You
>> could then make a formula based on the population size for the point
>> symboliser size.
>>
>> perhaps: 256.0*(POPULATION / 8000000000.0)
>
> I think what you are saying is possible only the way I proposed it.
> We have no way to add a point sybolizer to the polygon layer, so first
> he has to create a point layer (centroid) and the rest is the same as
> my workflow, right?
>
> Andrea
>
>
>>
>> --
>> Jody Garnett
>>
>> On Saturday, 5 May 2012 at 3:34 PM, andrea antonello wrote:
>>
>> Hi,
>>
>> I have a shape file with polygon, in my attributes I have the population of
>> each polygon.
>> I would like to have a representation where I can see the polygon and, one
>> circle representing the population for one polygon .
>> It should be like the attached file.
>> Is it possible with udig ?
>>
>>
>> right now I think you would need a step for getting the shown result.
>>
>> That is what I would do:
>> - create a layer of the baricenters of the polygons (we will use a
>> points layer) -> reshape operation, see:
>> http://udig.refractions.net/confluence/display/EN/Constraint+Query+Language
>> for the functions you can use
>> - in the same operation I also would create a new field that
>> normalizes the population value (you will use that as field that
>> defines the size of the point)
>>
>> So the reshape operation would look like:
>>
>> the_geom=baricenter(the_geom)
>> size=population/maxvalue
>>
>> That will create you a new layer that will then produce the style you want.
>>
>> Jody is working a lot on reshape and filters these days, so it might
>> already be easier.
>>
>> Cheers,
>> Andrea
>>
>>
>>
>>
>> best regards
>> Thomas
>>
>> --
>> Thomas DOLLEY
>> Projet GUYASIM
>> UMR ECOFOG
>> Bātiment D
>> TA C-105 / D Campus international de Baillarguet 34398 Montpellier Cedex 5
>> France
>> Tél : +33 4 67 59 38 85
>>
>>
>>
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