[GRASS-user] Import .shp, clean topology

Rich Shepard rshepard at appl-ecosys.com
Mon Aug 17 15:20:24 PDT 2020


Environment: grass7.9.dev updated 17 August on Slackware-14.2/x86_64.

I have a land use shapefile and created a new location for it based on the
.prj file. Importing via v.in.ogr grass suggested re-importing with a snap
distance. I did this 7 times, each using the gradually incrasing snap
distance (and requiring 30-45 minutes each run on a workstation with a
Ryzen7 2700 (8 cores/16 threads) and 16G RAM) until grass ran out of
suggested snap distances and suggesting I clean the file.

This I did, with the following warnings:
WARNING: Number of centroids exceeds number of areas: 728722 > 717454
WARNING: Number of incorrect boundaries: 261472
WARNING: Number of centroids outside area: 10722
WARNING: Number of duplicate centroids: 1144

When I reprojected this cleaned map to its storage location the same
warnings were reported.

Recognizing these are warnings, not errors, I ask what (if anything) should
I do about them.

TIA,

Rich



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