[postgis-devel] [PostGIS] #1639: [raster] MapAlgebraExpr can't handle conditions

[PostGIS]

#1639: [raster] MapAlgebraExpr can't handle conditions
---------------------+------------------------------------------------------
 Reporter:  nicklas  |       Owner:  pracine      
     Type:  defect   |      Status:  new          
 Priority:  high     |   Milestone:  PostGIS 2.0.0
Component:  raster   |     Version:  trunk        
 Keywords:           |  
---------------------+------------------------------------------------------

Comment(by dustymugs):

 The following works for me using your expression...

 {{{
 DROP TABLE IF EXISTS test_mapalgebra;
 CREATE TABLE test_mapalgebra(
         rid serial PRIMARY KEY,
         rast raster
 );
 CREATE OR REPLACE FUNCTION make_test_raster()
         RETURNS void
         AS $$
         DECLARE
                 width int := 5;
                 height int := 5;
                 x int;
                 y int;
                 rast raster;
         BEGIN
                 rast := ST_MakeEmptyRaster(width, height, 0, 0, 1, -1, 0,
 0);
                 rast := ST_AddBand(rast, 1, '8BUI', 0, 0);

                 FOR x IN 1..width LOOP
                         FOR y IN 1..height LOOP
                                 rast := ST_SetValue(rast, 1, x, y,
 random() * 256);
                         END LOOP;
                 END LOOP;

                 INSERT INTO test_mapalgebra (rast) VALUES (rast);

                 RETURN;
         END;
         $$ LANGUAGE 'plpgsql';
 SELECT make_test_raster();
 SELECT make_test_raster();
 DROP FUNCTION make_test_raster();

 WITH foo AS (
         SELECT
                 ST_MapAlgebraExpr(a.rast, b.rast, '(([rast1]-[rast2]) >
 50)::int', '1BB') AS rast
         FROM test_mapalgebra a
         CROSS JOIN test_mapalgebra b
         WHERE a.rid = 1
                 AND b.rid = 2
 )
 SELECT
         (ST_BandMetadata(rast)).*,
         (ST_SummaryStats(rast)).*
 FROM foo;
 DROP TABLE IF EXISTS test_mapalgebra;
 }}}

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/1639#comment:7>
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