[GRASS-dev] [GRASS GIS] #2648: v.concave.hull fails with small number of points

[GRASS GIS]

#2648: v.concave.hull fails with small number of points
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  Reporter:  annakrat     |      Owner:  grass-dev@…
      Type:  defect       |     Status:  new
  Priority:  normal       |  Milestone:  7.0.1
 Component:  Addons       |    Version:  unspecified
Resolution:               |   Keywords:  concave hull
       CPU:  Unspecified  |   Platform:  All
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Comment (by mlennert):

 Replying to [ticket:2648 annakrat]:
 > Tested with 3, 4, 5 points, v.concave.hull fails. Depends on threshold
 and point configuration, too.
 >
 > {{{
 > ERROR: Input vector map contains no boundaries.
 > ...
 >  ['v.centroids', '--q',
 'input=concave_hull_tmp_31390_delaunay_borders_select',
 'output=concave_hull_tmp_31390_delaunay_areas_select'] ended with error
 > }}}

 AFAICT, the algorithm cannot calculate the hull because the threshold is
 too high. For now I've added a fatal error in the script with a hint about
 the threshold (r65495). I don't know if the algorithm could be improved to
 allow a less concave hull even with such small number of points.

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Ticket URL: <http://trac.osgeo.org/grass/ticket/2648#comment:3>
GRASS GIS <http://grass.osgeo.org>