Could you give it a try?
> -----Original Message----- > From: [email protected] [mailto:postgis-users- > [email protected]] On Behalf Of Andreas Forø Tollefsen > Sent: Thursday, October 27, 2011 11:00 AM > To: PostGIS Users Discussion > Subject: Re: [postgis-users] Raster geomval return integer > > Hi, I have 1.8.1 > "POSTGIS="2.0.0SVN" GEOS="3.3.1-CAPI-1.7.1" PROJ="Rel. 4.7.1, 23 September > 2009" GDAL="GDAL 1.8.1, released 2011/07/09" LIBXML="2.7.8" > USE_STATS" > Should i update to latest subversion? > > Andreas > > 2011/10/27 Pierre Racine <[email protected]>: > > Ticket 650 was fixed in PostGIS and in the GDAL trunk. The ticket says "New > GDAL polygonize function implemented in GDAL release 22476 ( > http://trac.osgeo.org/gdal/changeset/22476). Please, update your GDAL copy > to a release" > > > > What version of libgdal do you have? > > > >> -----Original Message----- > >> From: [email protected] > >> [mailto:postgis-users- [email protected]] On Behalf Of > >> Andreas Forø Tollefsen > >> Sent: Thursday, October 27, 2011 7:59 AM > >> To: PostGIS Users Discussion > >> Subject: Re: [postgis-users] Raster geomval return integer > >> > >> Replying to my own post. > >> > >> Just to confirm my belief I used the raster calculator in QGIS and > >> calculated 'rast*100'. > >> Then imported it to postgis and ran the query again: > >> > >> SELECT gid,(foo.geomval).val, > >> CAST(SUM(ST_Area((foo.geomval).geom)) AS decimal(8,5)) as area, > >> CAST(SUM(ST_Area((foo.geomval).geom))/0.25*100 AS decimal(6,3)) as > >> percentarea FROM (SELECT p.gid, > >> ST_Intersection(ST_SetSRID(p.cell,4326), > >> ST_SetSRID(r.rast,4326), 1) AS geomval FROM mountain r, priogrid_land > >> p WHERE ST_Intersects(ST_SetSRID(p.cell,4326), > >> ST_SetSRID(r.rast,4326),1)) AS foo WHERE gid = 183230 AND > >> (foo.geomval).val >= 0 GROUP BY gid, (foo.geomval).val ORDER BY gid; > >> > >> Result: > >> 183230;74;0.00000;0.000 > >> 183230;33;0.00694;2.778 > >> 183230;80;0.00000;0.000 > >> 183230;16;0.00694;2.778 > >> 183230;9;0.00694;2.778 > >> 183230;100;0.04167;16.666 > >> 183230;73;0.00694;2.778 > >> 183230;89;0.00694;2.778 > >> 183230;71;0.00694;2.777 > >> 183230;22;0.00694;2.778 > >> 183230;35;0.00000;0.000 > >> 183230;48;0.00000;0.000 > >> 183230;59;0.00694;2.778 > >> 183230;0;0.13889;55.555 > >> 183230;12;0.00000;0.000 > >> 183230;6;0.00694;2.778 > >> 183230;1;0.00695;2.778 > >> > >> I can of course do this with any raster including a decimal pixel > >> value, but I really would like to not have to. > >> > >> Any ideas? > >> > >> Andreas > >> > >> > >> 2011/10/27 Andreas Forø Tollefsen <[email protected]>: > >> > Hi all, > >> > > >> > I have been working on this issue previously, but now we have > >> > updated to rev 8001 and the ticket 650 is fixed. > >> > Hence, I wanted to see if I can calculate the average pixelvalue > >> > within my grid cells (.5x.5 decimal degrees). > >> > > >> > However, I now experience that any value above 0 becomes 1, and i > >> > do not get the actual averaged value. > >> > I also tested to group by the polygonized pixel value, and this > >> > revealed that everything other than 0 is 1. > >> > According to my raster this is not correct, since I have many other > >> > values within the cells borders (see jpg). > >> > > >> > I have tried to use the ST_Value(rast, > >> > ST_SetSRID(ST_Point(lat,long)) and this give me the correct pixel values. > >> > However, I do not understand what is giving me integer values using > >> > the query below. > >> > > >> > Any ideas on what is wrong with my query? > >> > > >> > Query: > >> > SELECT gid,CAST(((foo.geomval).val) AS decimal(8,6)) AS mntval, > >> > CAST(SUM(ST_Area((foo.geomval).geom)) AS decimal(8,5)) as area, > >> > CAST(SUM(ST_Area((foo.geomval).geom))/0.25*100 AS decimal(6,3)) as > >> > percentarea FROM (SELECT p.gid, > >> > ST_Intersection(ST_SetSRID(r.rast,4326), > >> > ST_SetSRID(p.cell,4326)) AS geomval FROM mountain r, priogrid_land > >> > p WHERE ST_Intersects(ST_SetSRID(p.cell,4326), > >> > ST_SetSRID(r.rast,4326))) AS foo WHERE gid = 183230 AND > >> > (foo.geomval).val >= 0 GROUP BY gid, (foo.geomval).val ORDER BY > >> > gid; > >> > > >> > Result: > >> > 183230;1.000000;0.06945;27.778 > >> > 183230;0.000000;0.18055;72.222 > >> > > >> > > >> > Best, > >> > Andreas > >> > > >> _______________________________________________ > >> postgis-users mailing list > >> [email protected] > >> http://postgis.refractions.net/mailman/listinfo/postgis-users > > _______________________________________________ > > postgis-users mailing list > > [email protected] > > http://postgis.refractions.net/mailman/listinfo/postgis-users > > > _______________________________________________ > postgis-users mailing list > [email protected] > http://postgis.refractions.net/mailman/listinfo/postgis-users _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
