Hi,
IMHO, I would not complicate the driver for that. Such options would
actually be quite generic, and if we wanted to implement them, they
would probably better be implemented as options of ogr2ogr (but should
be done separately from your driver submission)
Even
Le 26/01/2024 à 10:59, Abel Pau via gdal-dev a écrit :
Hi again,
I understand...
Perhaps an option could be using something like *-lco
Z_NODATA_VALUE_DST="X"* to translate NODATA from origin to this value
X (NaN, 0, or whatever it may be). The driver can offer this number
instead of the own NODATA and the user can know that the X value in
destination will mean NODATA.
On the other hand, a user could also specify *-lco
Z_NODATA_VALUE_SRC="Y"* so that a driver can identify a value
considered NODATA in the source and translate it to the own NODATA
value (or the one specified by the first parameter (if it exists)).
Is this too complicated? Are there any repercussions that I'm not seeing?
Thanks.
*De:*Rahkonen Jukka <jukka.rahko...@maanmittauslaitos.fi>
*Enviado el:* dijous, 25 de gener de 2024 18:27
*Para:* Abel Pau <a....@creaf.uab.cat>; gdal-dev@lists.osgeo.org
*Asunto:* Re: vector NODATA for Z values?
Hi,
I think that it depends on the file format. Rather often it is set to
zero but I have seen NaN in many places. However, shapefiles
explicitly denies NaN
“…Positive infinity, negative infinity, and Not-a-Number (NaN) values
are not allowed in shapefiles. Nevertheless, shapefiles support the
concept of "no data" values, but they are currently used only for
measures. Any floating point number smaller than –1038 is considered
by a shapefile reader to represent a "no data" value.
With the SQLite dialect it is possible to select the value but NaN is
not accepted.
Can be tested with
ogrinfo -dialect SQLite -sql "select CastToXYZ(ST_GeomFromText('POINT
(1 2)'),3)" point.json
-Jukka Rahkonen-
*Lähettäjä:*gdal-dev <gdal-dev-boun...@lists.osgeo.org> *Puolesta
*Abel Pau via gdal-dev
*Lähetetty:* torstai 25. tammikuuta 2024 19.07
*Vastaanottaja:* gdal-dev@lists.osgeo.org
*Aihe:* [gdal-dev] vector NODATA for Z values?
Hi,
there is any value in GDAL for VECTORS that indicates that a concrete
value of a Z is not known (z nodata value)?
I couldn’t find it anywhere.
In MiraMon format we use one concrete number documented in our format
pdf (-1.0E+300) an in the driver it’s planned to translate it to the
same number. I could translate it to the one I am asking. And the same
for detecting nodata Z and translate them to -1.0E+300 when reading
another format.
Thanks!
*Abel Pau Garcia*
*GIS developer*
https://www.creaf.cat/sites/default/files/creaf-signature.png
*a....@creaf.uab.cat* <mailto:a....@creaf.uab.cat>
*Let's chat on Teams!*
<https://teams.microsoft.com/l/chat/0/0?users=a....@creaf.uab.cat>
*Tel. +34 934814277*
https://www.creaf.cat/sites/default/files/so-en-signature.png
https://www.creaf.cat/sites/default/files/twitter-icon-signature.png
<https://twitter.com/CREAF_ecologia>https://www.creaf.cat/sites/default/files/linkedin-icon-signature.png
<https://www.linkedin.com/company/1363052?trk=tyah&trkInfo=clickedVertical:company,clickedEntityId:1363052,idx:2-1-2,tarId:1465807877789,tas:creaf>https://www.creaf.cat/sites/default/files/youtube-icon-signature.png
<https://www.youtube.com/c/creafecologia>https://www.creaf.cat/sites/default/files/instagram-icon-signature.png
<https://www.instagram.com/CREAF_ecologia/>
*www.creaf.cat* <http://www.creaf.cat/>*| **http://blog.creaf.cat*
<http://blog.creaf.cat/>
https://www.creaf.cat/sites/default/files/uab_logo_signatura.png
CREAF. Campus UAB. Edifici C. 08193 Bellaterra (Barcelona)
Before printing this electronic message, think about the environment.
http://www.creaf.uab.cat/_signatura/line.gif
_______________________________________________
gdal-dev mailing list
gdal-dev@lists.osgeo.org
https://lists.osgeo.org/mailman/listinfo/gdal-dev
--
http://www.spatialys.com
My software is free, but my time generally not.
_______________________________________________
gdal-dev mailing list
gdal-dev@lists.osgeo.org
https://lists.osgeo.org/mailman/listinfo/gdal-dev
