What is the exact query you do when trying to compute the sum or the max of the resulting raster?
> -----Original Message----- > From: postgis-users-boun...@lists.osgeo.org [mailto:postgis-users- > boun...@lists.osgeo.org] On Behalf Of g.si...@utwente.nl > Sent: Monday, February 24, 2014 3:44 PM > To: postgis-users@lists.osgeo.org; postgis-users-ow...@lists.osgeo.org > Subject: [postgis-users] ST_MapAlgebraExpr 2 rasters problem with > resultant raster > Importance: High > > Hi, > > > > I am using ST_MapAlgepraExpr for the intersection of two rasters. > > The first raster has minimum and maximum values as 5.112e-020 and > 0.000125 respectively. > > The second raster has minimum and maximum value as 0.000 and > 0.000400 respectively. > > > > I carry the raster intersection using expression > > ST_MapAlgebraExpr(a.rast1,b.rast2, '[rast1.val] * [rast2.val]', '32BF', > 'INTERSECTION', 'NULL', 'NULL') > > And got a resultant raster whose value ranges from 0.000 to 1.862e-008. > > > > When I query the resultant raster for sum(ST_Summarystats(rast)) or > max(ST_Summarystats(rast)) I get the blank cell with double precision > datatype. > > > > I can visualize the raster and can see the sum of all cell values, max and min > cellvalues in ILWIS software but can not calculate the same using postgis > queries. > > > > Is there something wrong in my above map algebra expression or there is a > problem with map algebra function? > > > > Can someone please provide any solution to this problem. > > > > Thanks in Advance. > > Gaurav _______________________________________________ postgis-users mailing list postgis-users@lists.osgeo.org http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users