Gdal is honoring the no-data value encoded in the raster file, but postgis is not. I see this problem in a lot of code out there.
THK On Wed, Aug 21, 2013 at 2:26 PM, Hailey Eckstrand <[email protected] > wrote: > Hello, > I am trying perform aggregate statistics on a raster vector overlay with a > polygon of 192 sub polys. Many of the resulting 192 mean values are > correct.. however, I am encountering that one vector overlay mean is NULL > which I know to be incorrect. The polygon and raster are in the same > projection and when I look at them in QGIS they are overlaid correctly and > I can see that the polygon is over top of ~30 raster cells that are all the > value 3 (it is not over top of any NA values). One thing that is sort of > fishy is that QGIS is reading the raster statistics and no data value > incorrectly (values included below) compared to the base ascii raster > gdalinfo which is included below. > > My query: > > select bid,(ST_SummaryStatsAgg(ST_Clip(rast,1, geom, true))).mean > FROM aet_1,(select * from zben_allwshds where bid = 61) foo > WHERE ST_Intersects(rast, geom) > GROUP BY bid > order by bid; > NOTICE: The two rasters provided have no intersection. Returning no band > raster > CONTEXT: PL/pgSQL function "st_clip" line 39 at assignment > NOTICE: Could not find raster band of index 1 when setting pixel value. > Nodata value not set. Returning original raster > CONTEXT: PL/pgSQL function "st_clip" line 41 at assignment > NOTICE: Invalid band index (must use 1-based). Returning NULL > CONTEXT: PL/pgSQL function "raster_summarystatsstate" line 9 at assignment > SQL function "raster_summarystatsstate" statement 1 > bid | mean > -----+------ > 61 | > > > Query which returns all the Summary Stats (order of stats is count | sum | > mean | stddev | min | max) > > select bid,(ST_SummaryStatsAgg(ST_Clip(rast,1, geom, true))) > FROM aet_1,(select * from zben_allwshds where bid = 61) foo > WHERE ST_Intersects(rast, geom) > GROUP BY bid > order by bid; > NOTICE: The two rasters provided have no intersection. Returning no band > raster > CONTEXT: PL/pgSQL function "st_clip" line 39 at assignment > NOTICE: Could not find raster band of index 1 when setting pixel value. > Nodata value not set. Returning original raster > CONTEXT: PL/pgSQL function "st_clip" line 41 at assignment > NOTICE: Invalid band index (must use 1-based). Returning NULL > CONTEXT: PL/pgSQL function "raster_summarystatsstate" line 9 at assignment > SQL function "raster_summarystatsstate" statement 1 > bid | st_summarystatsagg > -----+-------------------- > 61 | (,237,,,3,3) > > > > The raster was loaded into postgresql with the raster2pgsql tool: > > raster2pgsql -s 3005 -I -C -M aet_1.asc -F -t 100x100 public.aet_1 | psql > -d NWBC > > gdalinfo of the loaded raster: > > gdalinfo aet_1.asc > Driver: AAIGrid/Arc/Info ASCII Grid > Files: aet_1.asc > aet_1.asc.aux.xml > Size is 2331, 2895 > Coordinate System is `' > Origin = (173461.904000000009546,1929781.912000000011176) > Pixel Size = (400.000000000000000,-400.000000000000000) > Corner Coordinates: > Upper Left ( 173461.904, 1929781.912) > Lower Left ( 173461.904, 771781.912) > Upper Right ( 1105861.904, 1929781.912) > Lower Right ( 1105861.904, 771781.912) > Center ( 639661.904, 1350781.912) > Band 1 Block=2331x1 Type=Float32, ColorInterp=Undefined > Min=0.000 Max=9.000 > Minimum=0.000, Maximum=9.000, Mean=1.955, StdDev=2.375 > NoData Value=-9999 > Metadata: > STATISTICS_MAXIMUM=9 > STATISTICS_MEAN=1.9546895049572 > STATISTICS_MINIMUM=0 > STATISTICS_STDDEV=2.3747620319231 > > Incorrect QGIS Raster Statistics: > > STATISTICS_MAXIMUM=1.2341209168929e+033 > > STATISTICS_MEAN=5.9293249344197e+031 > > STATISTICS_MINIMUM=-9999 > > STATISTICS_STDDEV=2.4574481861697e+032 > > NODATA VALUE= -32768 > > PostGIS raster info: > > rid serial NOT NULL, > rast raster, > filename text, > CONSTRAINT aet_1_pkey PRIMARY KEY (rid), > CONSTRAINT enforce_height_rast CHECK (st_height(rast) = 100), > CONSTRAINT enforce_max_extent_rast CHECK > (st_coveredby(st_convexhull(rast), > '0103000020BD0B000001000000050000001D5A643BAF2C0541FCA9F1D2EB7D27411D5A643BAF2C0541FED478E935723D41448B6CE7954B3141FED478E935723D41448B6CE7954B3141FCA9F1D2EB7D27411D5A643BAF2C0541FCA9F1D2EB7D2741'::geometry)), > CONSTRAINT enforce_nodata_values_rast CHECK > (_raster_constraint_nodata_values(rast)::numeric(16,10)[] = > '{-9999}'::numeric(16,10)[]), > CONSTRAINT enforce_num_bands_rast CHECK (st_numbands(rast) = 1), > CONSTRAINT enforce_out_db_rast CHECK (_raster_constraint_out_db(rast) = > '{f}'::boolean[]), > CONSTRAINT enforce_pixel_types_rast CHECK > (_raster_constraint_pixel_types(rast) = '{32BF}'::text[]), > CONSTRAINT enforce_same_alignment_rast CHECK (st_samealignment(rast, > '0100000000000000000000794000000000000079C01D5A643BAF2C0541FED478E935723D4100000000000000000000000000000000BD0B000001000100'::raster)), > CONSTRAINT enforce_scalex_rast CHECK (st_scalex(rast)::numeric(16,10) = > 400::numeric(16,10)), > CONSTRAINT enforce_scaley_rast CHECK (st_scaley(rast)::numeric(16,10) = > (-400)::numeric(16,10)), > CONSTRAINT enforce_srid_rast CHECK (st_srid(rast) = 3005), > CONSTRAINT enforce_width_rast CHECK (st_width(rast) = 100) > > > > Install info: > > PostgreSQL Version 9.1 > > postgis_full_version: > POSTGIS="2.0.1 r9979" GEOS="3.3.8-CAPI-1.7.8" PROJ="Rel. 4.8.0, 6 March > 2012" GDAL="GDAL 1.9.2, released 2012/10/08" LIBXML="2.7.8" TOPOLOGY RASTER > (1 row) > > QGIS version: > 1.8.0-Lisboa > Compiled against GDAL/OGR > 1.9.2 > Running against GDAL/OGR > 1.9.2 > GEOS Version > 3.3.8 > PostgreSQL Client Version > 8.3.10 > > > Sorry for all the extra information, I just don't know what people need to > know to help. Thanks in advance! > > Hailey > > > _______________________________________________ > postgis-users mailing list > [email protected] > http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users > > -- http://www.keittlab.org/
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