Could this have to do with the tiling of the raster? I will try to run the same query with a untiled mountain raster to see if that changes anything.
Btw. When loading a tiled postgis raster into qgis it shows up with many artifacts and no data areas. The same raster untiled does not show up the same way. Qgis bug? Andreas 2011/11/25 Andreas Forø Tollefsen <[email protected]> > Hi, > > Thanks for all of the suggestions. I will do some more testing. However, > as for suggestion 1 i think the pixel size should be the same as the > original raster or am I wrong? > > Both the mean_mnt_bin raster and the priogrid_land shapefile can be > downloaded as zip (2 mb) here: > http://gisintersect.com/mean_mnt_bin.zip > http://gisintersect.com/priogrid_land.zip > > Any help on getting the correct values would be very much appreciated. > > My query: > DROP TABLE IF EXISTS mountain_cell; > > SELECT > a.gid As id, > (ST_SummaryStats((ST_Union(ST_MapAlgebraExpr(ST_AsRaster(a.cell, b.rast, > '32BF'), b.rast, 'rast2', '32BF','INTERSECTION','0','0',0))).rast, > false)).mean As avgmnt > INTO mountain_cell > FROM > priogrid_land a LEFT JOIN > mountain b > ON ST_Intersects(a.cell, b.rast) > GROUP BY a.gid > ORDER BY a.gid; >
_______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
