> I have used ST_MapAlgebraExpr but I get the error below. > > > select * from (select ST_MapAlgebraExpr(kb.rast, kb1.rast, > 'kb1.rast+kb.rast') as > rast from kb_dsm_clip kb, kb_dsm_clip100 kb1) as r1 limit 5; > ERROR: missing FROM-clause entry for table "kb1" > LINE 1: SELECT (KB1.RAST+KB.RAST)::double precision ^ > QUERY: SELECT (KB1.RAST+KB.RAST)::double precision
Try this instead: SELECT ST_MapAlgebraExpr(kb.rast, kb1.rast, 'rast1 + rast2') as rast FROM kb_dsm_clip kb, kb_dsm_clip100 kb1 WHERE st_intersects(kb.rast, kb1.rast) 1) There is no need for a subquery 2) You must refer to the raster using 'rast1' and 'rast2', not their real names 3) I don't know if your rasters are tiled but it is always a good idea to restrict the process to intersecting footprints. Pierre _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
