[GRASS-dev] [GRASS GIS] #3430: v.clean threshold in lat-long: metric or not?

[GRASS GIS]

#3430: v.clean threshold in lat-long: metric or not?
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  Reporter:  neteler      |      Owner:  grass-dev@…
      Type:  defect       |     Status:  new
  Priority:  normal       |  Milestone:  7.2.3
 Component:  Vector       |    Version:  7.2.2
Resolution:               |   Keywords:  v.clean
       CPU:  Unspecified  |   Platform:  Unspecified
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Comment (by mmetz):

 Replying to [comment:2 mmetz]:
 > Replying to [comment:1 mlennert]:
 > > Replying to [ticket:3430 neteler]:
 > [...]
 > > >
 > > > Should the G_important_message() be removed from main.c?
 > >
 > > Looking through the code, I actually have the feeling that the
 documentation is wrong, at least for some of v.clean's functionalities.
 > [...]
 > >
 > > So while area calculations might use meters (i.e. the rmarea function
 mentioned in the SE message), I'm not sure this is the case for snapping
 distances... I think this needs very careful review before deciding what
 to do.
 >
 > I suggest to remove the message, because the message does not
 distinguish between the different cleaning tools. For tool=rmarea, the
 threshold must always be in square meters as stated in the manual.
 Otherwise, I'm pretty sure that the threshold is map units, also for
 latlon.

 According to https://gis.stackexchange.com/questions/258089/v-clean-with-
 rmarea-and-lat-long-projection there is another issue with v.clean
 tool=rmarea because it might remove areas that should not be removed. A
 test dataset would be helpful.

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Ticket URL: <https://trac.osgeo.org/grass/ticket/3430#comment:3>
GRASS GIS <https://grass.osgeo.org>