[postgis-devel] [PostGIS] #576: 3d distance functions

[PostGIS]

#576: 3d distance functions
-------------------------+--------------------------------------------------
 Reporter:  nicklas      |       Owner:  nicklas      
     Type:  enhancement  |      Status:  assigned     
 Priority:  medium       |   Milestone:  PostGIS 2.0.0
Component:  postgis      |     Version:  trunk        
 Keywords:               |  
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Changes (by bitner):

 * cc: bitner (added)


Comment:

 Further 3D measurements without resorting to using linear referencing to
 extract closest points etc would be awesome.  As to index usage, the 3D
 distance is always going to be longer than 2D case, so the same BOX2D
 expansion will still be valid (just less selective). The following should
 still be valid, no?

 CREATE OR REPLACE FUNCTION public.st_dwithin(geometry, geometry, double
 precision)
   RETURNS boolean AS
 'SELECT $1 && ST_Expand($2,$3) AND $2 && ST_Expand($1,$3) AND
 _ST_DWithin3d($1, $2, $3)'
   LANGUAGE 'sql' IMMUTABLE
   COST 100;

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Ticket URL: <http://trac.osgeo.org/postgis/ticket/576#comment:4>
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