Ciao Jeremy,
please, find my answer inline below...
Regards,
Simone Giannecchini
==
Our support, Your Success! Visit http://opensdi.geo-solutions.it for more
information.
==
Ing. Simone Giannecchini
@simogeo
Founder/Director
GeoSolutions S.A.S.
Via Poggio alle Viti 1187
55054 Massarosa (LU)
Italy
phone: +39 0584 962313
fax: +39 0584 1660272
mob: +39 333 8128928
http://www.geo-solutions.it
http://twitter.com/geosolutions_it
-------------------------------------------------------
On Wed, Feb 19, 2014 at 9:55 PM, Jeremy Lindsey <lind...@mosaicatm.com>wrote:
> Hello,
>
> I'm working on a project that has gridded weather data, stored in a
> postgis database. The database isn't really doing anything special with
> it, just entering one record (including a geometry column) for each cell in
> the grid. For hi-resolution weather information, this means that it can
> produce a large number of records.
>
> Until now, we have been using WFS to filter and retrieve the regions that
> we want and draw the results in our OpenLayers based web interface. We
> have javascript code that sets the color for each small polygon based on
> the value of another attribute of each feature. For one example, this
> could be percentage likelihood of precipitation or other weather. The end
> result basically looks like a heat map with higher percent regions having a
> more intense color than the lower percentage areas.
>
> As I mentioned though the dataset and be quite large. Unless you are
> filtering down to a pretty small area, then the query and rendering just
> takes too long. So the last couple days I've been experimenting with
> retrieving the data as a WMS layer instead of a WFS/vector layer. The
> results are promising. The data is properly filtered and returns much
> faster. (I beleive this is because its just returning a fixed 256x256
> image that does not need to grow in size like the raw WFS/GML would). The
> only problem is I can't figure out how to color it properly. By default,
> it was using the red point style and it all returned red. I tried other
> raster based styles, but since my data was not truly returned as raster, it
> failed (at least I assume that is why it failed).
>
If I got this right, you should use vector styles not raster styles. Your
data is vector data not raster data.
One question the geometry is a polygon or a point? I guess it should be a
polygon.
Check this page for reference:
http://docs.geoserver.org/stable/en/user/styling/sld-cookbook/polygons.html
It contains a lot of info on Polygon styles.
It might be of interest to use the CSS extension for styling:
http://docs.geoserver.org/latest/en/user/extensions/css/cookbook.html
>
> I then came across the vector-to-raster based heatmap style that could be
> applied via WPS. I installed the extension and tried the gs:heatmap as
> explained here:
>
>
> http://docs.geoserver.org/stable/en/user/styling/sld-extensions/rendering-transform.html
>
> I made a couple adjustments to fit my schema and gridval values (between
> 50 and 100) and assigned some random colors. It does not throw any
> exceptions, but I also do not see any colors showing up on my map. I have
> attached the style definition that I'm currently trying to use.
>
>
Thinking, it might be that the output values are too close to 0 and they
come out as white. Try to replace your RasterSymbolizer with this one:
<RasterSymbolizer>
<!-- specify geometry attribute to pass validation -->
<Geometry>
<ogc:PropertyName>geom</ogc:PropertyName></Geometry>
<Opacity>1.0</Opacity>
<ColorMap type="ramp" >
<ColorMapEntry color="#000000" quantity="0" label="black"/>
<ColorMapEntry color="#FFFFFF" quantity="100" label="white"
/>
</ColorMap>
</RasterSymbolizer>
If the values are ok (which means the transformation is applied correctly)
they should come out as grayscale (the rastersymbolizer by default applies
a linear ramp).
Let us know how it goes.
> As you have probably guessed, a lot of these concepts are still pretty new
> to me. I'd appreciate any tips that any of you might have to help me
> figure this out.
>
> Thanks!
>
> Jeremy
>
>
> ------------------------------------------------------------------------------
> Managing the Performance of Cloud-Based Applications
> Take advantage of what the Cloud has to offer - Avoid Common Pitfalls.
> Read the Whitepaper.
>
> http://pubads.g.doubleclick.net/gampad/clk?id=121054471&iu=/4140/ostg.clktrk
> _______________________________________________
> Geoserver-users mailing list
> Geoserver-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/geoserver-users
>
>
------------------------------------------------------------------------------
Flow-based real-time traffic analytics software. Cisco certified tool.
Monitor traffic, SLAs, QoS, Medianet, WAAS etc. with NetFlow Analyzer
Customize your own dashboards, set traffic alerts and generate reports.
Network behavioral analysis & security monitoring. All-in-one tool.
http://pubads.g.doubleclick.net/gampad/clk?id=126839071&iu=/4140/ostg.clktrk
_______________________________________________
Geoserver-users mailing list
Geoserver-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/geoserver-users
