The first one shows the total count of georeferenced articles per square kilometer and also depicts the so called featured articles (excellent and worth reading).

The next map shows the growth of wikipedia articles from February to December 2010.

With GeoTools/Geoserver there are similar extension points as well – although somewhat hidden. So here is a little sample for a custom geometry transformation function one can add to the GeoTools rendering module.

First create a java class that extends from org.geotools.filter.FunctionExpressionImpl and implement your geometry manipulation function inside the #evaluate method. If you need some examples, look at the existing classes that extend from FunctionExpressionImpl.

Second, to register that class to the GeoTools service provider interface: add a file named “org.opengis.filter.expression.Function” to the “META-INF/services” directory of your JAR file and add a line with the full class name of the java class (that one extending from FunctionExpressionImpl) to this file.

Third, create a JAR with your class and the META-INF and add it to the Geoserver’s classpath.

Fourth, create a SLD style where this new geometry function is used:

  <FeatureTypeStyle>
    <Rule>
      <PolygonSymbolizer>
        <Geometry>
           <ogc:Function name="magic">
              <ogc:PropertyName>the_geom</ogc:PropertyName>
              <ogc:PropertyName>bld_height</ogc:PropertyName>
           </ogc:Function>
        </Geometry>
        <Stroke>
          <CssParameter name="stroke">#888888</CssParameter>
          <CssParameter name="stroke-width">0.6</CssParameter>
        </Stroke>
      </PolygonSymbolizer>
    </Rule>
  </FeatureTypeStyle>

Voilá… oh I forgot to say, that of course you can pass other attributes from the feature to your function class – like with my example the attribute “building height” to control the height of the 3D wire frame.

However, I was somewhat astonished when I read this article in Computerworld, whereto: “..95% is more accurate today”. Do I hear 105%? Somewhere? Oh and by the way, did you know: 95% of all food contains water.

You might want to have a look at these two intelligent videos from Peter Batty of Enspiria about why we need Smart Grids and the technology behind it.

The new "ZDF heute" Look and Feel

But wait, why are they using this WWII-era-like antiquated cylindrical map projection for their new world map (looks like Miller projection)? Where Russia seems to be almost four times larger than China and (of course) Greenland as large as South America!

Don’t get me wrong. I’m not that Peters projection fundamentalist, like those cartographers from the TV series West Wing. But, in fact, there are far better choices for world map projections with better compromises between shape and area distortions than a cylindrical projection. For instance Winkel Tripel or the Robinson projections.

I’ve got another question too – why some areas in the map are raised and others are lowered – like Mexico is shifted below the US? Actually that question appeared at the ZDF’s internet forum as well. The answer was: it’s an artist’s impression (not a map!) – it looks more pleasant this way :) Any questions left, huh? Read Mark Monmonier’s How to Lie with Maps!

Here is how it works:

<echo file="uploadlog.ctl">
    <![CDATA[
load data
infile *
replace
into table MYLOBTABLE
fields terminated by ','
(
lobid char(100),
lob_file FILLER char,
clobdata LOBFILE(lob_file) TERMINATED BY EOF
)
begindata
transferlog,${sqllog.file}]]>
</echo>
<ora:sqlldr logon="user/pass@oradb">
	control = uploadlog.ctl
</ora:sqlldr>

First I write a temporary CTL file (with the <echo> task) to specify that I want to upload the file behind the ${sqllog.file} property, afterwards I execute this CTL file with the SQL*Loader.

And jeez, I can even upload whole filesets (directories and sub directories) when I use the <for> loop task.

I strongly agree with Dave Bouwman’s assumption that this is the result of a long lasting strategy of trying to cram desktop GIS into the browser with GIS manufacturers concentrating on developing utterly generic “out-of-the-box” WebGIS products. So this wants us GIS developers make to believe that we are able to produce WebGIS applications in a jif. But the simple fact is that 99% of so called WebGIS apps have a quite narrow purpose, thus need pretty focused functions and user interfaces instead of bloated generic UI’s.

Am I afraid of web designers eating my lunch?

… Nope, quite the contrary! Good web sites need a lot of knowlegde in usabilty design. And since web designers usually offer this kind of knowledge, I would appreciate a much closer collaboration with them. Web design actually is not my bread and butter. I would rather like to concentrate much more on things like backend GIS functions, geocoders, tile servers etc. In other words, as a GIS developer I’ll gladly share my lunch with web designers where this task-sharing increases my margin for more potentially feasible projects. Finally, I think this way everyone will get more lunch by letting everyone do what they do best.