[postgis-devel] [PostGIS] #894: _ST_Expand for geography is broken

[PostGIS]

#894: _ST_Expand for geography is broken
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 Reporter:  robe     |       Owner:  pramsey      
     Type:  defect   |      Status:  new          
 Priority:  blocker  |   Milestone:  PostGIS 2.0.0
Component:  postgis  |     Version:  1.5.X        
 Keywords:           |  
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Comment(by pramsey):

 Can you re-confirm? I get 'true' in PostGIS 2.0 for all your examples.

 Regards the first point, that expanding doesn't change the geometry, you
 are right, that it is the box being expanded, not the geography. More to
 the point, it's not possible to represent the box as a geography. The box
 is a 3d geocentric box. The geography is a set of 2d spherical
 coordinates. So expand grows the cached box but doesn't alter the
 coordinates of the object. This is why it's _ST_Expand(), because there's
 no way a user is ever going to grok the subtlety.

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Ticket URL: <http://trac.osgeo.org/postgis/ticket/894#comment:2>
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