[postgis-devel] [PostGIS] #1268: [raster] ST_MapAlgebraExpr for 2 rasters

[PostGIS]

#1268: [raster] ST_MapAlgebraExpr for 2 rasters
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 Reporter:  dustymugs       |       Owner:  pracine      
     Type:  task            |      Status:  new          
 Priority:  medium          |   Milestone:  PostGIS 2.0.0
Component:  postgis raster  |     Version:  trunk        
 Keywords:                  |  
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 Set of function variants for expression-based map-algebra for two rasters.

 1. ST_MapAlgebraExpr(
         rast1 raster, band1 integer,[[BR]]
         rast2 raster, band2 integer,[[BR]]
         expression text DEFAULT NULL,[[BR]]
         pixeltype text DEFAULT NULL, extenttype text DEFAULT
 'INTERSECTION',[[BR]]
         nodata1expr text DEFAULT NULL, nodata2expr text DEFAULT NULL,
 nodatanodataexpr text DEFAULT NULL
 )

 2. ST_MapAlgebraExpr(
         rast1 raster,[[BR]]
         rast2 raster,[[BR]]
         expression text DEFAULT NULL,[[BR]]
         pixeltype text DEFAULT NULL, extenttype text DEFAULT
 'INTERSECTION',[[BR]]
         nodata1expr text DEFAULT NULL, nodata2expr text DEFAULT NULL,
 nodatanodataexpr text DEFAULT NULL
 )

 Should we consider a different function name?  Something like
 ST_MapAlgebra2Expr?  Also, is there any reason why we have all the
 ST_MapAgebraXXX except for distinguishing the type of MapAlgebra?  I think
 there isn't any issue with calling all of the ST_MapAlgebraXXX functions
 ST_MapAlgebra due to the different signatures.

 The code I've written for this function can definitely be modularized so
 that there are separate parts, some of which will be done for
 ST_MapAlgebraFct of 2 raster.

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/1268>
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