[postgis-devel] [PostGIS] #1005: [raster] Problem with ST_SummaryStats(text, text) results

[PostGIS]

#1005: [raster] Problem with ST_SummaryStats(text, text) results
----------------------------+-----------------------------------------------
 Reporter:  pracine         |       Owner:  pracine      
     Type:  defect          |      Status:  new          
 Priority:  medium          |   Milestone:  PostGIS 2.0.0
Component:  postgis raster  |     Version:  trunk        
 Keywords:                  |  
----------------------------+-----------------------------------------------
 I can observe some problems with the numbers returned by the coverage
 variant of ST_SummaryStats

 1) The sum is the sum of the last tile only. Not of the whole coverage.

 2) For a raster coverage of two rasters created like this:

 {{{

 --First test raster
 CREATE OR REPLACE FUNCTION ST_TestRaster1()
     RETURNS raster AS
     $$
     DECLARE
         newrast raster := ST_AddBand(ST_MakeEmptyRaster(2, 2, 0, 0, 1, 1,
 0, 0, -1), '32BUI'::text, 0, -1);
     BEGIN
         newrast := ST_SetValue(newrast, 1, 1, 1);
         newrast := ST_SetValue(newrast, 1, 2, 3);
         newrast := ST_SetValue(newrast, 2, 1, 3);
         newrast := ST_SetValue(newrast, 2, 2, 1);
         RETURN newrast;
     END;
     $$
     LANGUAGE 'plpgsql';

 --Second test raster
 CREATE OR REPLACE FUNCTION ST_TestRaster2()
     RETURNS raster AS
     $$
     DECLARE
         newrast raster := ST_AddBand(ST_MakeEmptyRaster(2, 2, 2, 2, 1, 1,
 0, 0, -1), '32BUI'::text, 0, -1);
     BEGIN
         newrast := ST_SetValue(newrast, 1, 1, 1);
         newrast := ST_SetValue(newrast, 1, 2, 2);
         newrast := ST_SetValue(newrast, 2, 1, 3);
         newrast := ST_SetValue(newrast, 2, 2, 4);
         RETURN newrast;
     END;
     $$
     LANGUAGE 'plpgsql';

 --Create table
 DROP TABLE sumstattest;
 CREATE TABLE sumstattest AS
  SELECT ST_TestRaster2() rast
  UNION ALL
  SELECT ST_TestRaster1() rast;

 }}}

 {{{

 SELECT * FROM st_summarystats('sumstattest', 'rast');

 }}}

 should return 1.089724736 not 1.06066017770915.

 Result verified with the stdev.p function in Excel.

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/1005>
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