Opened 16 months ago

Last modified 10 months ago

#859 new defect

Voronoi issue

Reported by: jjgreen Owned by: geos-devel@…
Priority: major Milestone: 3.6.4
Component: Default Version: 3.5.1
Severity: Unassigned Keywords:


OSGEO Voronoi issue

Further to a posting on the PostGIS mailing list in February 2018, this directory contains scripts to generate data for the bug report for OSGEO. The scripts generating the data can only be used against a copy of the seadb DB which is not open source, but the script can be used (with minimal modifications) to reproduce the issue with the CSV file output from the DB.

For my setup, which is Ubuntu Xenial with PostGIS from and

  • POSTGIS="2.3.3 r15473"
  • GEOS="3.5.0-CAPI-1.9.0 r4084"
  • PROJ="Rel. 4.9.2, 08 September 2015"
  • GDAL="GDAL 1.11.3, released 2015/09/16"
  • LIBXML="2.9.3"
  • LIBJSON="0.11.99" RASTER

the script reports

CREATE TABLE COPY 1322 CREATE INDEX ERROR: GEOSVoronoiDiagram: TopologyException?: Input

geom 1 is invalid: Self-intersection at or near point 444332.38647522771 8548816.0569835864 at 444332.38647522771 8548816.0569835864

As discussed in the PostGIS forum thread mentioned above, we find that ST_SnapToGrid with dyadic grid step fixes the issue.

The original data for these points was the EuroROSE project, an EU-funded experiment on the feasibility of the use of HF-radar for measuring ocean waves, currents and so on. The experiment took place at Fedje, Norway in early 2000. More details can be found at

Attachments (2)

fedje.csv (73.6 KB) - added by jjgreen 16 months ago.
data points (514 bytes) - added by jjgreen 16 months ago.
script which reproduces the issue

Download all attachments as: .zip

Change History (4)

Changed 16 months ago by jjgreen

Attachment: fedje.csv added

data points

Changed 16 months ago by jjgreen

Attachment: added

script which reproduces the issue

comment:1 Changed 11 months ago by robe


Still an issue even with 3.7.0beta1.

comment:2 Changed 10 months ago by robe

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