[postgis-tickets] [PostGIS] #2422: geography regression difference ST_DWithin

[PostGIS]

#2422: geography regression difference ST_DWithin
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 Reporter:  robe     |       Owner:  pramsey      
     Type:  defect   |      Status:  new          
 Priority:  high     |   Milestone:  PostGIS 2.1.2
Component:  postgis  |     Version:  2.1.x        
 Keywords:           |  
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Comment(by robe):

 pramsey,

 I have a potentially stupid question to ask.  I see that: FP_LT macro is
 defined as


 {{{
  FP_LT  (A,
         B        )                         (((A) + FP_TOLERANCE) < (B))

 }}}

 which is used here:
 http://postgis.net/docs/doxygen/2.1/de/dc0/lwgeodetic__tree_8c_a337b8cc452a495c52080254b042536c0.html#a337b8cc452a495c52080254b042536c0

 Wouldn't that mean that when I define a threshold of X, it is really
 treating it as
 X + FP_TOLERANCE ?

 So If I happen to hit a node that is between X and (X + FP_TOLERANCE)  it
 would kick out success.

 But my  X < threshold would fail?

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/2422#comment:37>
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