Hi,
Validity checks don't check the file format. They check the validity of
the geometries once they are read from the file into the software.
The shape file format is a partly documented format. It is very easy to
write a shape file which is not according to the specs. To my experience
ESRI software will do that every now and again. Very probably you have
one of those shape files.
You might ask the person who created the files to:
- buffer the geometries with a distance of 0 and the save the resulting
file again.
- and/or export to a different file format (eg geopackage)
Regards, MArco
On 29-10-19 09:19, Casper Børgesen wrote:
Hi Pepa
I have tried loading and exporting the multipolygons as WKT using
OGR/python and it looks like the holes are interpreted as polygons.
FME displays the data (correctly?) with holes and its validation
engine doesn’t find any errors. BUT a year ago I sent a bug report to
SAFE because FME did some automatic geometry repair when loading data
=> the various programs could be fixing issues automatic which means
you won’t see them. Not to imply that ESRI does automatic geometry
repair in the background, but which program can you definitely trust
to correctly represent the contents of your data set?
I tend to trust GDAL/OGR (which means I also trust QGIS) because its
open source and the developers are normally pretty good at reporting
back how the software treats data.
My reply doesn’t fix your problem though, just a few thoughts from me.
Regards, Casper
*From:*gdal-dev <[email protected]> *On Behalf Of *Pepa
Beneš
*Sent:* 29. oktober 2019 08:10
*To:* [email protected]
*Subject:* [gdal-dev] Fwd: Gdal - multipolygon - geometry errors
instead holes
HI,
I recieved one shapefile. Gdal / Grass / QGIS finds two geometry
errors in it. Other GIS SW (ArcMap, MapInfo (via Universal translator
or opening shp natively)) theay can't see this geometries as errors.
Instead errors they can see regular multipolygons with holes there.
Author of this shp wants to see holes there too = in his opinion there
are correct data only.
Please, write me, how to work with such geometries in gdal / grass /
QGIS / geos world to see holes too, instead errors?
In geometry_problem.zip
<https://drive.google.com/file/d/1oRJQVKYDkZji-GLmobov995m9vF00vwf>
there are:
geometry_problem.qgz .. vizualization in QGIS
original.shp .. original data prepared in ESRI
original_esri.png .. original.shp seen in ArcMap (With holes. Author
of shp wants have holes there.)
original_errors.shp .. geometry errors prepared by "QGIS Desktop 3.8.3
with GRASS 7.6.1"
original_qgis.png .. original.shp seen in QGIS
MI/original_to_MI_by_UN.tab .. original.shp translated from shp to tab
by MapInfo - UniversalTranslator (tried defferent versions with the
same results).
Thanks
Pepa Beneš
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