[postgis-users] Creating a Flow Diagram

[Bob Pawley]

I 'm playing with a variation of the st_translate function we were 
discussing last week.

I have created two boxes (spatial_ref) and I wish to place an entity 
(graphics.process_dgm) into the temp_ table with the coordinates that 
centers the entity in a specific one of these boxes.

Here's the code that I have come up with but so far it produces 0 rows.

 Insert into temp_ (the_geom)
 Select st_translate(st_translate (graphics.process_dgm.the_geom,
  st_y (st_centroid(graphics.process_dgm.the_geom)) - st_x (st_centroid 
(spatial_ref.the_geom)),
  st_y (st_centroid(graphics.process_dgm.the_geom)) - st_y (st_centroid 
(spatial_ref.the_geom))),
  ( st_xmax(graphics.process_dgm.the_geom) - 
st_xmin(graphics.process_dgm.the_geom)),
  ( st_ymax(graphics.process_dgm.the_geom) - 
st_ymin(graphics.process_dgm.the_geom)))
 from graphics.process_dgm, spatial_ref, temp_
 where graphics.process_dgm.description = 'Tank'
 and spatial_ref.position_ = '2';


Thoughts will be appreciated.

Bob