On Mon, Jun 23, 2008 at 9:08 PM, Markus Neteler <[EMAIL PROTECTED]> wrote: > Rainer, > > I suggest to try the snap parameters of v.in.ogr first. Maybe the SHAPE > file is full of gaps and slivers (commonly found, even in governmental > data). > *Small* snapping values might cure it. Be careful to not snap, say, > Africa to a triangle :) > > Markus
Thanks Markus, but the information is there. If I display the layer and select layer=2, I see the overlapping areas, and if I click i=on them to get information (v.what -a [EMAIL PROTECTED] ...), I get the following info: East: 255207.46888 North: 6235456.43154 Map: fireHistory Mapset: simulation Type: Centroid Line: 3202 Layer: 1 Category: 4 Driver: dbf Database: /home/rkrug/Documents/Projects/AlienSpread/R/../grass/simulation/dbf/ Table: fireHistory Key column: cat cat : 4 YEAR : 2005 Layer: 1 Category: 178 Driver: dbf Database: /home/rkrug/Documents/Projects/AlienSpread/R/../grass/simulation/dbf/ Table: fireHistory Key column: cat cat : 178 YEAR : 1993 Layer: 1 Category: 208 Driver: dbf Database: /home/rkrug/Documents/Projects/AlienSpread/R/../grass/simulation/dbf/ Table: fireHistory Key column: cat cat : 208 YEAR : 1995 Layer: 2 Category: 3 <<--- and the one value marked by <<-- is the one which IO want to extract into a raster or vector map. Even if I do v.extract [EMAIL PROTECTED] output=fires type=point,line,boundary,area layer=2 it gives me the areas, but no associated attribute table. > > On Mon, Jun 23, 2008 at 12:13 PM, Rainer M Krug <[EMAIL PROTECTED]> wrote: >> >> Hi >> >> I am importing a vector layer from a shape file as follow, and get the >> warning below: >> >> > v.in.ogr dsn=/home/rkrug/Documents/Projects/AlienSpread/data/input/ >> > layer=fireHistory output=fireHistory --overwrite >> >> >> WARNING: 703 areas represent more (overlapping) features, because polygons >> overlap in input layer(s). Such areas are linked to more than 1 >> row in attribute table. The number of features for those areas is >> stored as category in layer 2 >> >> >> I am aware of that, and I want to create a raster layer with the >> number of features overlapping in each location. As I ultimately need >> a raster layer, I thought to use the following, but I get the error >> message below: >> >> > v.to.rast input=fireHistory layer=2 output=mf use=attr column=category >> > --overwrite >> >> ERROR: Unable to get layer info for vector map >> >> Why is that? >> >> Is there another way of getting the number of overlapping features per >> cell? >> >> Thanks >> >> Rainer >> >> >> -- >> Rainer M. Krug, PhD (Conservation Ecology, SUN), MSc (Conservation >> Biology, UCT), Dipl. Phys. (Germany) >> >> Plant Conservation Unit >> Department of Botany >> University of Cape Town >> Rondebosch 7701 >> South Africa >> _______________________________________________ >> grass-user mailing list >> grass-user@lists.osgeo.org >> http://lists.osgeo.org/mailman/listinfo/grass-user > > > > -- > Open Source Geospatial Foundation > http://www.osgeo.org/ > http://www.grassbook.org/ -- Rainer M. Krug, PhD (Conservation Ecology, SUN), MSc (Conservation Biology, UCT), Dipl. Phys. (Germany) Plant Conservation Unit Department of Botany University of Cape Town Rondebosch 7701 South Africa _______________________________________________ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
