[GRASS-dev] [GRASS GIS] #3030: v. generalize fails to generalize polygons in a random manner

[GRASS GIS]

#3030: v. generalize fails to generalize polygons in a random manner
---------------------+--------------------------
  Reporter:  dido    |      Owner:  grass-dev@…
      Type:  defect  |     Status:  new
  Priority:  major   |  Milestone:  7.0.5
 Component:  Vector  |    Version:  7.0.4
Resolution:          |   Keywords:  v.generalize
       CPU:  x86-64  |   Platform:  MSWindows 7
---------------------+--------------------------

Comment (by mmetz):

 Replying to [comment:8 dido]:
 > Hi,
 >
 > the reason why non-generalized polygons appear in the output is
 certainly clear. My point is that none of these polygons will be damaged
 due to generalization over-simplification, so I suspect a v.generalize
 algorithm problem here.
 >
 > As an example find attached 4 pairs of shapefiles that produce non-
 simplified polygons.

 I modified v.generalize a bit in my local copy to write out those modified
 boundaries that would damage topology. In each of your test cases.
 v.generalize is correct in not generalizing these boundaries. They would
 collapse to a point, intersect with themselves, intersect with another
 boundary, or produce a zero-size area. See screenshots in attached
 topo_errors.zip.

--
Ticket URL: <https://trac.osgeo.org/grass/ticket/3030#comment:9>
GRASS GIS <https://grass.osgeo.org>