[postgis-devel] [PostGIS] #381: Add an optional parameter to ST_Scale to specify the anchor point

[PostGIS]

#381: Add an optional parameter to ST_Scale to specify the anchor point
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 Reporter:  kneufeld     |       Owner:  kneufeld     
     Type:  enhancement  |      Status:  new          
 Priority:  low          |   Milestone:  PostGIS 2.1.0
Component:  postgis      |     Version:  trunk        
 Keywords:               |  
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Comment(by mwtoews):

 For CAD systems, you need to specify a point of origin, not just midpoint
 or corner. A similar enhancement for ST_Rotate (#1251) could also be
 adapted for ST_Scale to provide:
 {{{
 ST_Scale (geometry geomA, float XFactor, float YFactor, [float ZFactor,]
 geometry pointOrigin);
 }}}
 then a user could do, for example:
 {{{
 -- Scale down feet to metres from the top left corner
 SELECT ST_Scale(geom, 0.3048, 0.3048, ST_MakePoint(ST_XMin(geom),
 ST_YMax(geom)));

 -- Scale up by 2x from centre
 SELECT ST_Scale(geom, 2.0, 2.0, ST_Centroid(geom));
 }}}

-- 
Ticket URL: <https://trac.osgeo.org/postgis/ticket/381#comment:3>
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