[postgis-devel] [PostGIS] #1525: [raster] Redefine and expand the keywords available to MapAlgebra expressions

PostGIS trac at osgeo.org
Fri Feb 3 06:43:19 PST 2012


#1525: [raster] Redefine and expand the keywords available to MapAlgebra
expressions
-------------------------+--------------------------------------------------
 Reporter:  dustymugs    |       Owner:  pracine      
     Type:  enhancement  |      Status:  new          
 Priority:  critical     |   Milestone:  PostGIS 2.0.0
Component:  raster       |     Version:  2.0.x        
 Keywords:               |  
-------------------------+--------------------------------------------------

Comment(by dustymugs):

 Replying to [comment:20 strk]:
 > Note that #1119 is about enhancing expressivity further to take into
 account band number.
 > Using [n] for addressing a band number wouldn't be that readable inside
 brackets.
 > I wonder if we could find a general syntax capable of addressing
 multiple rasters (rather than only 1 or 2) and multiple bands in them.
 >
 > Like:
 >
 > {{{
 > :rast[1].band[2].val
 > :rast[2].band[1].x
 > }}}
 >
 > Or, if we prefer square brackets:
 >
 > {{{
 > [rast1.band2.val]
 > [rast2.band1.x]
 > }}}
 >
 > With defaults:
 >
 > {{{
 > [rast.band2.y] -- defaults to rast1
 > [rast3.band.val] -- defaults to band1
 > [rast.x] -- defaults to rast1.band1.x
 > [rast] -- defaults to rast1.band1.val
 > }}}

 You may want to put this in the other ticket (#1119) as this feels like it
 is better suited there.

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/1525#comment:21>
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