Opened 3 years ago

Last modified 13 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:
Cc:

Description

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 reproduce.sh 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 apt-postgresql.org 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 reproduce.sh 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

http://wera.cen.uni-hamburg.de/EuroROSE/EuroROSE_Intro.shtml

Attachments (2)

fedje.csv (73.6 KB) - added by jjgreen 3 years ago.
data points
reproduce.sh (514 bytes) - added by jjgreen 3 years ago.
script which reproduces the issue

Download all attachments as: .zip

Change History (8)

Changed 3 years ago by jjgreen

Attachment: fedje.csv added

data points

Changed 3 years ago by jjgreen

Attachment: reproduce.sh added

script which reproduces the issue

comment:1 Changed 2 years ago by robe

Milestone: 3.5.23.7.0

Still an issue even with 3.7.0beta1.

comment:2 Changed 2 years ago by robe

Milestone: 3.7.03.6.4

comment:3 Changed 15 months ago by komzpa

Hi, there was a gridded voronoi robustness fix in #976. Maybe this one is fixed on master too?

comment:4 Changed 15 months ago by mdavis

This problem does appear to be caused by input points which lie on a grid, so this is probably fixed by #976

comment:5 Changed 13 months ago by pramsey

Not fixed, just tested on latest trunk.

comment:6 Changed 13 months ago by Paul Ramsey <pramsey@…>

In 2036448/git:

Add trimmed down test case on Voronoi.
Curiously, this case blows an exception on PostGIS, but not in the unit test.
References #859

Note: See TracTickets for help on using tickets.