[postgis-devel] [PostGIS] #1154: ST_Area returns wrong results for big geography polygon [-179.9 -89.9 179.9 89.9 ]

PostGIS trac at osgeo.org
Fri Aug 5 04:13:37 PDT 2011


#1154: ST_Area returns wrong results for big geography polygon [-179.9 -89.9 179.9
89.9 ]
-------------------------+--------------------------------------------------
  Reporter:  mvimercati  |       Owner:  pramsey                        
      Type:  defect      |      Status:  closed                         
  Priority:  high        |   Milestone:                                 
 Component:  postgis     |     Version:  1.5.X                          
Resolution:  wontfix     |    Keywords:  ST_Area geography big huge area
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Changes (by robe):

  * status:  new => closed
  * resolution:  => wontfix


Comment:

 Vime,

 I believe this is an implementation limitation. The geography type is not
 guaranteed to be right for arcs greater than a half hemispherre.  In fact
 is pretty guaranteed to be wrong for  calculations for geographies with
 arcs greater than 180.  That's a limitation of it because of the way
 calculations are done.  This is known and don't think we plan to fix this
 in the forseeable near feature.

 Take a look at the FAQ: #4.2.3.3 for details:
 http://www.postgis.org/documentation/manual-
 svn/using_postgis_dbmanagement.html#PostGIS_Geography_AdvancedFAQ

 If I misunderstood you, please feel free to reopen this ticket.

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/1154#comment:1>
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