[postgis-devel] [PostGIS] #503: ST_Area on small polygons in EPSG:31467 gives incorrect results depending on 32-/64-system-architecture

[PostGIS]

#503: ST_Area on small polygons in EPSG:31467 gives incorrect results depending
on 32-/64-system-architecture
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  Reporter:  mjansen  |       Owner:  pramsey      
      Type:  defect   |      Status:  new          
  Priority:  medium   |   Milestone:  PostGIS 1.5.2
 Component:  postgis  |     Version:  1.5.X        
Resolution:           |    Keywords:               
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Comment (by nicklas):

 Mark

 I commented away the whole row since that was the only of NUMERIC_FLAGS,
 but I see no difference. Same problem in windows.

 Fromwhat I have understood we have this problem on windows 32 bit and
 linux 64 bit. Has anyone had the problem on a linux 32 bit system?

 Another interesting note, if I run the calculation directly in postgresql
 like this:

 {{{
 select ( x1 * y2) - ( y1 * x2 ) from
 (select
 3498246.2563 as x1,
 5815493.2389 as x2,
 3498246.2472 as y1,
 5815493.1259 as y2) a
 }}}
 then I get exactly the same answer (-342380.83848791) on both platforms.
 Not exactly the same as inside postgis in any of the cases but quite close
 to the answer from ubuntu 32 bit which seems to give the right area.

 I guess that makes it more likely that the problem is isolated to postgis.

 /Nicklas

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/503#comment:14>
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