> The result is that I change raster values in only 1 of the 81 polygon cells > that I have in > schema.data_vector. What am I missing here? Thanks for your help! Keep > up the great work!
UPDATE schema.data_raster SET rast = ST_SetValue(rast,1, geom, 100) FROM schema.data_vector I don't fully understand the behavior of UPDATE in that case but, or it join with only one row of schema.data_vector, or it join with all of them but only the last one is used to update schema.data_raster. Or actually probably schema.data_raster is updated many times but always from the original value. Not incrementally. Hugues suggestion: SELECT rid, ST_SetValue(rast,1, geom, 100) AS RAST FROM schema.data_raster, schema.data_vector Would produce as many raster rows as you have geometries... There are two better ways to do this... The first one is to ST_Union the rasterizization of the geometries and to union it with the existing raster: SELECT ST_Union(rast, 'LAST') rast FROM (SELECT rast FROM schema.data_raster UNION ALL SELECT ST_Union(ST_AsRaster(geom, rast, '16BSI', elevation, -10000)) rast FROM schema.data_raster, schema.data_vector ) foo You can probably assign this single result as an UPDATE to your table.. The second one is to install the PostGIS Add-ons from https://github.com/pedrogit/postgisaddons/releases and to do something like: SELECT ST_ExtractToRaster(ST_AddBand(ST_MakeEmptyRaster(rast), '16BSI'), 'schema', 'geomtable', 'data_vector', 'elevation', 'MEAN_OF_VALUES_AT_PIXEL_CENTROID') rast FROM schema.data_raster; You can probably also assign this single result as an UPDATE to your table... Pierre _______________________________________________ postgis-users mailing list postgis-users@lists.osgeo.org http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
