Hello Hemant, The discussion continued in the thread you linked (see next messages in the thread). I used the -c flag of v.in.ogr to avoid cleaning polygons when importing the shapefile as I needed the simple features to extract zonal stats from raster maps afterwards. Would that be useful to you too in this case?
Vero El sáb, 19 feb 2022 a las 0:23, B H (<[email protected]>) escribió: > I have data in a Shapefile which has genuine cases of overlapping > geometries. (As documented in v.in.ogr) the common areas appear with > multiple categories. > I need to find these common areas and "dedupe" them. > Currently I export the data out via v.out.ogr and in postgis do select > distinct on (st_asbinary(geometrycomlum)) from tablename order by > priorityattribute > > Is there some way to either dedupe it in grass Gis itself, or have > v.out.ogr output some common attribute in the two geometries that > represent the common area > from two polygons. > There is a similar question in this old thread. However I could not find > the solution. > https://lists.osgeo.org/pipermail/grass-user/2019-May/080293.html > > > > > --- > clip from v.in.ogr man page describing how the overlapping polygons are > handled. > > Overlapping polygons > When importing overlapping polygons, the overlapping parts will become new > areas with multiple categories, one unique category for each original > polygon. An original polygon will thus be converted to multiple areas with > the same shared category. These multiple areas will therefore also link to > the same entry in the attribute table. A single category value may thus > refer to multiple non-overlapping areas which together represent the > original polygon overlapping with another polygon. The original polygon can > be recovered by using v.extract with the desired category value or where > statement and the -d flag to dissolve common boundaries > Thanks, > Hemant > > _______________________________________________ > grass-user mailing list > [email protected] > https://lists.osgeo.org/mailman/listinfo/grass-user >
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