[GRASS-dev] [GRASS GIS] #2401: v.distance in Long/Lat Locations

[GRASS GIS]

#2401: v.distance in Long/Lat Locations
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  Reporter:  micha        |       Owner:  grass-dev@…              
      Type:  defect       |      Status:  reopened                 
  Priority:  normal       |   Milestone:  6.4.5                    
 Component:  Vector       |     Version:  6.4.4                    
Resolution:               |    Keywords:  v.distance               
  Platform:  Unspecified  |         Cpu:  Unspecified              
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Changes (by mlennert):

  * status:  closed => reopened
  * resolution:  fixed =>


Comment:

 Replying to [comment:3 neteler]:
 > Replying to [comment:2 mlennert]:
 > > I've applied the patch in r61859 and r61860.
 > >
 > > Closing this ticket.
 >
 > Are the results identical to that of GRASS GIS 7 latest SVN?

 For point to point and point to line they seem to be equal, but there are
 differences with point to area. I'll attach a file with results of the
 following command:


 {{{
 v.distance -p from=comm_colleges to=urbanarea upload=cat,dist
 col=to_cat,dist dmin=0.0001
 }}}

 in grass6 and grass7.

 For some points (to_cats 3,7,8,12,15,23,24,25,27,32,34,43,46,48,49,52,54),
 the distances are different. However, in the grass6 version they are
 similar to the distances calculated in the original NC-NAD83 projection,
 whereas the grass7 version gives different results.

 I don't know if this is a general bug in the distance calculations in
 v.distance which is corrected in the geodesic distance of grass7, or
 whether the issue is in the geodesic distance calculation in grass7. I'm
 suspecting the latter, but Markus M would have to look at this.

 Reopening until we know for sure.

 Moritz

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Ticket URL: <https://trac.osgeo.org/grass/ticket/2401#comment:4>
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