[postgis-users] Error in raster import with WKTRaster

[Jorge Arévalo]

Hi Mathieu,

On Fri, Feb 11, 2011 at 1:20 AM, Mathieu Basille
<basille at ase-research.org> wrote:
> Dear users,
>
> I have a problem while trying to import a raster into PostGIS
> (2.0.0SVN), using WKTRaster (0.1.6d), on a Debian system.
>
> This is a raster exported from GRASS as GeoTiff, using a float32 format
> (this is a density map). I then used:
>
> mathieu at Caribou$ /usr/lib/postgresql/8.4/bin/gdal2raster.py -r
> RoadDensity_2002_2006_CV_UTM19_25m.tif -t
> roaddensity_2002_2006_cv_utm19_25m -s 26919 -k 50x50 -I >
> RoadDensity_2002_2006_CV_UTM19_25m.sql
>
> and finally to import into PostGIS, as the postgres user:
> postgres at Caribou:/home/mathieu$ psql -f
> RoadDensity_2002_2006_CV_UTM19_25m.sql geodb
> BEGIN
> psql:RoadDensity_2002_2006_CV_UTM19_25m.sql:2: NOTICE:  CREATE TABLE
> créera des séquences implicites «
> roaddensity_2002_2006_cv_utm19_25m_rid_seq » pour la colonne serial «
> roaddensity_2002_2006_cv_utm19_25m.rid »
> psql:RoadDensity_2002_2006_CV_UTM19_25m.sql:2: NOTICE:  CREATE TABLE /
> PRIMARY KEY créera un index implicite «
> roaddensity_2002_2006_cv_utm19_25m_pkey » pour la table «
> roaddensity_2002_2006_cv_utm19_25m »
> CREATE TABLE
> psql:RoadDensity_2002_2006_CV_UTM19_25m.sql:3: ERREUR:  la colonne « nan
> » n'existe pas
> LIGNE 1 : ...','rast',26919, ARRAY['32BF'], false, true, ARRAY[nan], 25.0...
>                                                               ^
> psql:RoadDensity_2002_2006_CV_UTM19_25m.sql:4: ERREUR:  la transaction
> est annulée, les commandes sont ignorées jusqu'à la fin du bloc
> de la transaction
> psql:RoadDensity_2002_2006_CV_UTM19_25m.sql:5: ERREUR:  la transaction
> est annulée, les commandes sont ignorées jusqu'à la fin du bloc
> de la transaction
> psql:RoadDensity_2002_2006_CV_UTM19_25m.sql:6: ERREUR:  la transaction
> est annulée, les commandes sont ignorées jusqu'à la fin du bloc
> de la transaction
> ...
>
> And it continues for every line (or until I stop it). In the end, the
> table is not imported at all. (sorry if parts of the ouputs are in
> French: the first error message is simply: "the column "nan" does not
> exist", and the next ones says "the transaction is cancelled, all
> commands will be ignored until the end of the bloc of the transaction")
>
> Note that this is the exact same approach that I am generally using,
> without any problem for other maps (including density maps as float32).
>
> I am new to PostGIS and the SQL world, so it might be an easy one...
> Yet, I still have no idea what's wrong here. I welcome any pointer!
>
> All the best,
> Mathieu.
>
>
> --
>
> ~$ whoami
> Mathieu Basille, Post-Doc
>
> ~$ locate
> Laboratoire d'Écologie Comportementale et de Conservation de la Faune
> + Centre d'Étude de la Forêt
> Département de Biologie
> Université Laval, Québec
>
> ~$ info
> http://ase-research.org/basille
>
> ~$ fortune
> ``If you can't win by reason, go for volume.''
> Calvin, by Bill Watterson.
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>

The error is caused because the NODATA value for the band is not a
number. Probably, the GetNodata function for this band returns NULL,
and this situation is not managed in the loader code. Let me check it
and open a new ticket if needed.

Anyway, you're using PostGIS 2.0SVN. With this version you don't need
WKTRaster 0.1.6d separately. Actually, WKTRaster 0.1.6d is not longer
mantained, and it probably will cause errors (like this) if you use it
with PostGIS from trunk.

The raster extension (now "PostGIS Raster" instead of WKTRaster) is
included as official part of PostGIS. You can enable it by compiling
PostGIS in this way:

./configure --with-raster
make
make install
createdb <your_database>
createlang plpgsql <your_database>
psql -f postgis/postgis.sql -d <your_database>
psql -f spatial_ref_sys.sql -d <your_database>
psql -f raster/rt_pg/rtpostgis.sql -d <your_database>

Now, you can load raster data in <your_database> with the new version
of the loader script: raster2pgsql.py (in
<postgis_src_root>/raster/scripts/python). Same syntax than the older
gdal2wktraster.py script.

Further information at
http://gis4free.wordpress.com/2010/10/01/wkt-raster-is-now-postgis-raster/

Best regards,

-- 
Jorge Arévalo
Internet & Mobilty Division, DEIMOS
jorge.arevalo at deimos-space.com
http://es.linkedin.com/in/jorgearevalo80
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