Archive for the ‘GIS’ Category

SDE – GeoTools Micro Dictionary

August 21, 2007

If you don’t know GeoTools and face the task of passing some application from SDE to GT, you may find this table useful for initial orientation in problem. The list of SDE classes very limited though.

SDE GeoTools GeoAPI JTS
SeCoordinateReference   org.opengis.referencing.crs.CoordinateReferenceSystem  
SePolygon     com.vividsolutions.jts.geom.Polygon
SePoint     com.vividsolutions.jts.geom.Point
SeExtent     com.vividsolutions.jts.geom.Envelope
SeRow org.geotools.feature.Feature    
SeLayer org.geotools.data.DataStore    
SeTable org.geotools.data.postgis.FeatureType    
SeShape     com.vividsolutions.jts.geom.Geometry
SeColumnDefinition org.geotools.feature.AttributeType    
SeQuery org.geotools.data.DataStore.getFeatures()    
SeRegistration no need – sde specific    
SDEPoint no need – sde specific    

Mapserver Enterprise vs Mapserver Cheetah

June 25, 2007

Note: I have rewritten this article after crtitics which was deserved a bit:-)

To whom it may concern.. This is still a bit naming mess. The two pieces of software have almost nothing to to do with each other.
“Mapserver Enterprise” simply does’n exist anymore and is now called MapGuide Open Source, open source approach to web mapping, based on original Autodesk’s code. Despite of the former name, there is no “child” version of UMN Mapserver nor fork, there’s one Mapserver. A bit of history – Autodesk entered in free GIS in 2005 with its MapGuide. As they were publishing a huge amount of code I think that they wanted to make it a big way. They invented these two names, but there was little response for calling Mapserver other names.. Now, the name “Mapserver Enterprise” is not promoted anymore and the product resides on http://mapguide.osgeo.org/. Anyway, some people from Autodesk still call it so – I have heard it recently on GlobalGeo in Barcelona. But it is probably only a mistake – Mapserver Enterprise simply doesn’t exist anymore.

MapGuide is not written in Java¬† as I originally thougt, but “entirely coded in cross-platform C++, using SWIG to generate the user-facing web APIs” (citing Jason Birch) and has some quite interesting features – i.e. using DXF vector plugin in browser, extensive ajax use etc. This comparing to old unix-like C/C++ mapserver may appear really to be anvaced edition. I certainly think that != true; Everybody can choose the best for his needs – oh wait there is already Geoserver! Cool J2EE app built with GeoTools.

From ESRI SDE to GeoTools

April 23, 2007

I am currently rewriting one spatially enabled application, that uses SDE now. I will pass it to GeoTools 2.3 that we could work towards PostGIS and later more data sources. Looking forward to have GDAL bindings in GT!
It will be a long way. To be continued…

Manual editing of .map file –

March 23, 2007

Yeah, it is a pain, especially when you have more layers. But it is not MapServer’s fault, since you have to put a lot of information in there!

For WMS and probably for other services, if you don’t put in LAYER’s tag METADATA line “ows_extent”, mapserver keeps computing the extent every time you make a getcapabilities request. You cannot put EXTENT tag into the LAYER only, because strange things happen – seems that depends on the datasource, when the LatLonBoundingBox tag appears. With “ows_extent” this everything OK. Mapserver 4.10

Next time I will have to write some .map manually I will generate it with some simple script!

yet another mapserver web client

March 21, 2007

Italian people do go on!

http://datacrossing.crs4.it/en_Documentation_mscross.html

how to use tiles in mapping

March 20, 2007

The answer is, I don’t know, except using gdaltindex. But, I know place where they know:

http://labs.metacarta.com/wms-c/

I hope to add some comments later and hope this helps out there.

 

WKT to proj conversion

March 20, 2007

Lately I have searched hard something I had in front of my eyes: I wanted to convert WKT text to proj4 definition. Search for “wkt2proj” didn’t really made it:-) But I found it, it’s name is testepsg and is part of gdal/ogr. It is not present in default build, but i.e. FWTools has it.

It basically converts WKT stored in .prj file into more formats: formated WKT, simplified WKT, old WKT and finally proj4 text.

testepsg ESRI::tmp/mywkt.prj

Hope it helps!