I think "v.dissolve" corrupted it. I solved it by making a raster map and then a vector map again.
Thanks, Markus and Pablo, Achim Achim Kisseler schrieb: > I made the grid with: > > -%<-- > v.mkgrid --overwrite map=$1_grid_all grid="$north_south,$east_west" > position=coor coor="$southwest_corner" box="0:30,0:30" > > echo " > ######################################## > ## shrink grid to land-surface" > sqlite3 $2 "drop table $1_grid_patched" > v.overlay --o ainput=$1_grid_all binput=$1_area output=$1_grid_patched > v.db.addcol map=$1_grid_patched columns="keep INT" > sqlite3 $2 "UPDATE $1_grid_patched SET keep=1 WHERE (NOT b_cat IS NULL > OR ((a_row*1000)+a_col) IN (SELECT (a_row*1000)+a_col FROM > $1_grid_patched WHERE NOT b_cat IS NULL))" > v.extract input=$1_grid_patched output=$1_grid_extracted where="keep=1" > --overwrite > v.db.addcol map=$1_grid_extracted columns="dissolve INT" > sqlite3 $2 "UPDATE $1_grid_extracted SET dissolve=((a_row*1000)+a_col)" > v.dissolve --overwrite input=$1_grid_extracted output=$1_grid > column=dissolve layer=1 > > (...) > > sh renew_cats.sh $1_grid 2 centroid > db.droptable -f table=$1_grid > v.db.connect -d map=$1_grid > v.db.addtable map=$1_grid > -%<-- > > In the picture: > yellow grids seem ok (301.444-279.003 km²) > one is 194.532 > the rest is 2.545.231-11.559.210 > > Achim > > > > Pablo Carreira schrieb: >> Achim, how was the grid generated? Could you put some fo the results here? >> >> >> Pablo. >> >> >>> Date: Mon, 7 Dec 2009 18:32:14 +0100 >>> From: a...@jupiter.uni-freiburg.de >>> To: markus.metz.gisw...@googlemail.com >>> Subject: Re: [GRASS-user] bug?: v.to.db wrong area >>> CC: grass-user@lists.osgeo.org >>> >>> Hi Markus, >>> >>> its the same with hectares; kilometers writes out the result in >>> square-kilometers. >>> >>> Achim >>> >>> Markus Metz schrieb: >>>> Achim Kisseler wrote: >>>>> Hi, >>>>> >>>>> I am using >>>>> >>>>> v.to.db map=af_grid option=area columns=area type=centroid >>>>> units=kilometers >>>>> >>>> try units=hectares, kilometers are not an areal unit, don't know why >>>> v.to.db executes at all >>>> >>>> you can cross-check the results by querying the map >>>> >>>> hope that helps, >>>> >>>> Markus M >>>> >>>>> (in GRASS65 opensuse 11.1 64) >>>>> >>>>> to calculate the area size. Some of the areas are very wrong. Its a >> grid >>>>> in lat-lon, where areas should be nearly equal in size. >>>>> >>>>> Is this a known bug? I don't guess so. >>>>> Do I something wrong? >>>>> >>>>> Thanks, >>>>> Achim >>>>> >>>>> PS: >>>>> already did v.clean, r.mask -r (<- should not be have an effect) >>>>> _______________________________________________ >>>>> grass-user mailing list >>>>> grass-user@lists.osgeo.org >>>>> http://lists.osgeo.org/mailman/listinfo/grass-user >>>>> >>>>> >>> _______________________________________________ >>> grass-user mailing list >>> grass-user@lists.osgeo.org >>> http://lists.osgeo.org/mailman/listinfo/grass-user >> ------------------------------------------------------------------------ >> Agora a pressa é amiga da perfeição. Chegou Windows 7. Conheça. >> <http://www.microsoft.com/brasil/windows7/default.html?WT.mc_id=1539> >> >> ------------------------------------------------------------------------ >> >> >> ------------------------------------------------------------------------ >> >> _______________________________________________ >> grass-user mailing list >> grass-user@lists.osgeo.org >> http://lists.osgeo.org/mailman/listinfo/grass-user _______________________________________________ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user