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<div class="moz-cite-prefix">On 25-01-17 16:57, Markus Metz wrote:<br>
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On Wed, Jan 25, 2017 at 12:31 PM, Paulo van Breugel <<a
moz-do-not-send="true"
href="mailto:p.vanbreugel@gmail.com"><a class="moz-txt-link-abbreviated" href="mailto:p.vanbreugel@gmail.com">p.vanbreugel@gmail.com</a></a>>
wrote:<br>
><br>
> Dear all,<br>
><br>
> I have a vector layer which I cleaned up using
v.clean. It all appears to be fine, but when trying to
export using the libkml in v.out.ogr and the type=area
option, I am getting the warning and error messages like
below:<br>
><br>
> Warning 1: Ring Self-intersection at or near point<br>
> 88.100626640406631 27.668444701473838<br>
> ERROR 6: Invalid polygon<br>
> Warning 1: Ring Self-intersection at or near point<br>
><br>
> In the resulting kml file, some of the polygons are
missing. If I use the kml output in v.out.ogr, I am not
getting any warnings, but similarly, some of the
polygons are missing.<br>
><br>
> When I import the layer in Spatialite and check the
geometries I am getting similar warnings / error
messages, e.g.,:<br>
><br>
> 27 Ring Self-intersection at or near point
82.397900772562522 29.707213605319616<br>
><br>
><br>
> How can I identify and clean these issues in GRASS?
Checking for topological errors with v.build does not
result in any error, and I tried the various tools in
v.clean to no avail.<br>
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Did you try<br>
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v.clean -c type=boundary tool=rmsa,break,rmdangle
threshold=0,0,-1<br>
?<br>
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Yes, I tried<br>
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<div>Also try v.build -e<br>
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Tried that too, it does not report any error.<br>
<br>
Generally where the boundaries of two polygons with the same
category touch each other by one point (illustrated below),
Spatialite and QGIS (both using geos) seem to report an error for
that point. <br>
<br>
<pre>+-----+ +
| | / \
| A |+ A +
| | \ /
+-----+ +
</pre>
<br>
I am not sure yet if that is what is causing the problem (missing
polygons) when exporting to kml. I am cleaning a layer now for
export. Will report how that worked out.<br>
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cite="mid:CAG+h=FGNizze3xfhA07h6Ya=92oqbxPG9pnNbcdAK99xZJBndw@mail.gmail.com"
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<div dir="ltr">Markus M<br>
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<div>><br>
> Paulo<br>
> _______________________________________________<br>
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