[GRASS-dev] [GRASS GIS] #3369: Followup to area calculation fix in changeset 71169

[GRASS GIS]

#3369: Followup to area calculation fix in changeset 71169
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  Reporter:  ndawson      |      Owner:  grass-dev@…
      Type:  defect       |     Status:  new
  Priority:  normal       |  Milestone:
 Component:  Default      |    Version:  unspecified
Resolution:               |   Keywords:
       CPU:  Unspecified  |   Platform:  Unspecified
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Comment (by mmetz):

 Replying to [comment:3 mmetz]:
 > Replying to [comment:2 ndawson]:
 > > > About the first example (regression14675): what is SRSid 145L in
 EPSG or proj4 terms?
 > >
 > > Argh, missed that sorry. It's EPSG:2154.
 >
 > Thanks! Here are the results
 >
 >  * QGIS reference: 0.83301
 >  * GRASS in EPSG:2154: 0.86121968362156
 >  * GRASS in latlon: 3.3238796585328
 >
 > I had to lower the threshold to 1e-8 in order to get
 >
 >  * GRASS in latlon: 0.86134805688084

 After I applied the advice in my own comment, a threshold of 1e-6 works
 fine

  * GRASS in latlon: 0.861746563835888

 If different latitudes are regarded as nearly identical (fabs(dy) <=
 thresh), then the average of the two latitudes must be used, not one of
 them.

 This correction is now also in relbr72 (r71260).

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Ticket URL: <https://trac.osgeo.org/grass/ticket/3369#comment:4>
GRASS GIS <https://grass.osgeo.org>