[Qgis-user] Voronoi issue

[Andrew Harfoot]

Hi list,

I have encountered an issue when creating Voronoi polygons from a point 
dataset using the native Voronoi polygons processing tool in QGIS 
3.40.7. I'm not sure whether this is a bug or not, so am asking for an 
opinion here before raising a ticket. I have attached an excerpt from a 
larger point dataset which causes the voronoi tool to fail with an error:

Feature could not be written to 
Voronoi_polygons_b838458f_b720_4604_8b19_e58370910ee7: Could not add 
feature with geometry type GeometryCollection to layer of type Polygon

Could not write feature into OUTPUT

Execution failed after 0.03 seconds

As far as I can tell, there is nothing unusual about these points, and 
they have come from a much larger dataset of 1.1 million points that all 
complete successfully.

If I export the points to a GeoJSON with the default 15dp precision, the 
error no longer arises, whereas increasing the precision to 20dp results 
in the error still occurring, the difference being in rownum = 15.

I'd like to understand why the error is arising so as to avoid similar 
issues in the future.

Cheers,

Andy

-- 
Andy Harfoot

GeoData Institute
University of Southampton
Southampton
SO17 1BJ

www.geodata.soton.ac.uk
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{
"type": "FeatureCollection",
"name": "SuspectPoints_20dp",
"crs": { "type": "name", "properties": { "name": "urn:ogc:def:crs:OGC:1.3:CRS84" } },
"xy_coordinate_resolution": 1e-20,
"features": [
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]
}
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{
"type": "FeatureCollection",
"name": "SuspectPoints_15dp",
"crs": { "type": "name", "properties": { "name": "urn:ogc:def:crs:OGC:1.3:CRS84" } },
"features": [
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}