data export tool

[Martin Tomko]

Thank you Frank (I was hoping for your reply, seems like you are always 
the person to ask things like this :))
I need to create my dataset (fast vectorization), and I am ready to 
chose whatever format is best to do this as fast as possible. I need a 
topology top test with my functional programming environment, but 
because I am NOT a full strength programmer, compiling c++ stuff and so 
one sounds more like a nightmare to me :)

A bit of scripting or SQL is ok :). So, you reckon that ArcINFO binary 
vectors would be best? ok, I will give it a try! Oh, I thing we should 
have such an extraction function in OGR by default!!  (at least for the 
poor scientists trying to tune up algorithms :)
Thanks
Martin


----------------------------------------------
Ing. Martin Tomko
PhD. candidate

CRC for Spatial Information
Department of Geomatics
University of Melbourne
Victoria 3010
Australia

phone +61 3 8344 9179
fax   +61 3 9349 5185
email m.tomko at pgrad.unimelb.edu.au
url   http://www.geom.unimelb.edu.au/tomko
url   http://www.spatialinformationscience.org
url   http://www.crcsi.com.au
----------------------------------------------

Frank Warmerdam wrote:
> On 10/13/05, Martin Tomko <m.tomko at pgrad.unimelb.edu.au> wrote:
> 
>>I am desperately seeking a tool/workflow o export vector data into
>>text/tables with basically the arc/node topological description of my data.
>>
>>So If I export polygons, I need a table with the polygon IS and the IDs
>>of all its arcs, without any coordinates. Does anyone know a way?
>>
>>I was thinking about postgress/postgis? Dump a shp in it and try an sql?
>>Would ogr2ogr do it somehow? I did not find a way to include the IDs of
>>the arcs of a polygon. Seems like export to CSV would help, but I need
>>to get the arcs IDs somehow.
> 
> 
> Martin,
> 
> You didn't mention what data you are starting with.  Is it a shapefile?
> If so, part of your problems is that you need to build the topology from
> a non-topological structure.   As Flavio mentioned, FME would be a
> good choice for that.  GRASS also has support for converting
> non-topological dataset to topological.
> 
> If you are already starting with a topological Arc/Info binary vector
> coverage, then you will see from the ogrinfo reports that the topology
> information is available as attributes.
> 
> OGRFeature(PAL):2
>   ArcIds (IntegerList) = (1:-349)
>   AREA (Real) =            0.92814
>   PERIMETER (Real) =            5.35872
>   COUNTRYD# (Integer) = 2
>   COUNTRYD-ID (Integer) = 3027
>   POLYGON ((-153.022781372070312 57.383213043212891,...
> 
> OGRFeature(ARC):1
>   UserId (Integer) = 1394
>   FNODE# (Integer) = 1
>   TNODE# (Integer) = 2
>   LPOLY# (Integer) = 24
>   RPOLY# (Integer) = 26
>   LINESTRING (56.360397338867188 25.983451843261719,...
> 
> The ArcIds on the polygons and the node/poly information on the
> arcs is enough to establish the topological relationships.   With a
> script or C++ program written on OGR you could get that information
> out into a text format of some kind.
> 
> If you use GRASS to export to E00 you could use avcimport to
> convert to a binary coverage for use with OGR.  FME can write
> binary coverages directly.  Of course, both FME and GRASS offer
> other mechanisms to interact with the topology that might be more
> direct.
> 
> Best regards,
> --
> ---------------------------------------+--------------------------------------
> I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
> light and sound - activate the windows | http://pobox.com/~warmerdam
> and watch the world go round - Rush    | Geospatial Programmer for Rent
>