[mapguide-users] Looking for geospatial data

[Frank Warmerdam]

Konstantinos Vassiliadis wrote:
> I have downloaded the VMAP0 dataset. I was wondering whether it is 
> possible to somehow import these data to MapGuide OS Viewer or some 
> other client. Essentially I am looking for geospatial data about a 
> specific region in Italy - preferrably to be available in the public 
> domain but if not it is ok.
> Any ideas please?

Konstantinos,

VMAP0 data in VPF format is pretty messy to work with.  In theory you can
build OGR with the OGDI add on driver, and use that to access VPF data
like VMAP0.  But that would be pretty challenging to get right.

Alternatively you could use an existing OGR+OGDI build and ogr2ogr to
translate the data you want into shapefiles or something similar that is
more accessable.  FWTools includes everything you need
(http://fwtools.maptools.org) but addressing VMAP0 data is still a bit
hard.  For a VMAP0 Eurasian CD dataset sitting on disk as /mnt/cdrom/v0eur
I would use the following datasource name for OGR:

   gltp:/vrf/mnt/cdrom/v0eur/vmaplv0/eurnasia

If you do an ogrinfo on that you will get layer names like:

1: libref at libref(*)_line (Line String)
2: libreft at libref(*)_text (Point)
3: tileref at tileref(*)_area (Polygon)
4: tilereft at tileref(*)_text (Point)
5: polbndp at bnd(*)_point (Point)
6: coastl at bnd(*)_line (Line String)
7: depthl at bnd(*)_line (Line String)
8: polbndl at bnd(*)_line (Line String)
9: oceansea at bnd(*)_area (Polygon)
...

You can copy one layer to a shapefile something like:

   ogr2ogr coastl.shp gltp:/vrf/mnt/cdrom/v0eur/vmaplv0/eurnasia \
           "coastl at bnd(*)_line" -nln coastl

But most interesting data from VMAP0 is available from other sources
as shapefiles so my real advice is to dig up one of those sources and
use it.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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