[GRASS-dev] [GRASS GIS] #1827: Measure Distance - Bearing

[GRASS GIS]

#1827: Measure Distance - Bearing
-----------------------+----------------------------------------------------
  Reporter:  voncasec  |       Owner:  grass-dev@…                         
      Type:  defect    |      Status:  closed                              
  Priority:  normal    |   Milestone:  6.4.3                               
 Component:  wxGUI     |     Version:  svn-releasebranch64                 
Resolution:  fixed     |    Keywords:  Bearing tool, MapFrame.MeasureDist()
  Platform:  Linux     |         Cpu:  x86-64                              
-----------------------+----------------------------------------------------
Changes (by hamish):

  * keywords:  Bearing tool => Bearing tool, MapFrame.MeasureDist()
  * resolution:  => fixed
  * status:  new => closed
  * component:  Display => wxGUI


Comment:

 yes, the N-S was calculated backwards in the wxGUI. fixed in all branches
 with r55801-4.

 It also now states the convention used, since this one is backwards as to
 how grass typically measures it. (here using navigational convention
 instead of mathematical one) If you want the standard GRASS way (reporting
 theta CCW from the +x axis) uncomment the line in frame.py as documented
 in the code.

 I am glad to see MapWindow.Distance using G_distance() via ctypes for
 geodesic distance in lat/lon. I wonder for LL if we should have frame.py
 check for meters as the unit, and report km instead if the distance is >
 2500.0?
 (btw, note if you want bearing in lat/lon locations there will be two
 different bearings, a forward and backward one from each endpoint. (see
 the man page for `geod`))


 Hamish

-- 
Ticket URL: <https://trac.osgeo.org/grass/ticket/1827#comment:2>
GRASS GIS <http://grass.osgeo.org>