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
