Thanks again. The shape is an sub-basin map the routing for a hydrological model is based on. So consecutive cats make it a bit easier to understand the routing of model- that all- ;-)
Cheers, Stefan On Mon, 2012-08-20 at 09:22 +0200, Moritz Lennert wrote: > On Fri, August 17, 2012 13:21, Stefan Luedtke wrote: > > Thanks, that did the trick. > > > > I guess, in order to get a consecutive "cat", I do have to reclass > > (v.reclass) the vector- or is there any shortcut? > > v.category option=del > v.category option=add > > but this will erase any connections to attributes that you might have. > > If you have attributes, v.reclass is probably your best bet. But why do > your cats have to be consecutive ? > > Moritz > > > > > > Sorry for the noise, but vector stuff in grass is still a bit confusing > > to me. > > > > Cheers, > > > > Stefan > > > > On Fri, 2012-08-17 at 11:38 +0200, Moritz Lennert wrote: > > > >> On 16/08/12 20:23, Stefan Luedtke wrote: > >> > That helped for my general understanding, thanks a lot, but I can not > >> > figure out how. > >> > > >> > Can anyone just give a few hints on the procedure, basically, how to > >> > continue after "v.clean", please? > >> > >> You could try using v.extract with something list list=1-9999 in order > >> to create a new vector file which contains only those polygons (and > >> their attributes in the table) which exist in your cleaned file. > >> > >> Moritz > >> > >> > > >> > Cheers, > >> > > >> > Stefan > >> > > >> > On Thu, 2012-08-16 at 16:29 +0200, Markus Metz wrote: > >> >> On Thu, Aug 16, 2012 at 1:10 PM, Stefan > >> Luedtke<[email protected] <mailto:[email protected]>> > >> wrote: > >> >> > Dear friends, > >> >> > > >> >> > I am struggling with the following point. > >> >> > > >> >> > I have created a shape of subbasins based on a raster data set. > >> Since this > >> >> > yields some tiny (pixel size) areas, I run"v.clean" with a > >> certain > >> >> > threshold to remove/append those artifacts. However, the resulting > >> vector > >> >> > data set still holds all categories of the old one, even so, some > >> areas have > >> >> > been removed. > >> >> > >> >> This is because several areas can belong to the same category, e.g. > >> >> basin id, and the category of a deleted area may still be used by > >> >> another, existing area. BTW, it is not uncommon that one raster basin > >> >> is represented by several vector areas. > >> >> > > >> >> > So my question: How can I update these values that the number of > >> categories > >> >> > matches the number of areas? > >> >> > >> >> You can delete the table and create a new table. Otherwise, entries > >> in > >> >> the attribute table that are no longer used do not do harm. > >> >> > >> >> HTH, > >> >> > >> >> Markus M > >> >> > >> >> > > >> >> > I tried v.category (but der is not update function). > >> >> > > >> >> > Cheers, > >> >> > > >> >> > Stefan > >> >> > > >> >> > _______________________________________________ > >> >> > grass-user mailing list > >> >> > [email protected] <mailto:[email protected]> > >> >> > http://lists.osgeo.org/mailman/listinfo/grass-user > >> >> > > >> > > >> > > >> > _______________________________________________ > >> > grass-user mailing list > >> > [email protected] > >> > http://lists.osgeo.org/mailman/listinfo/grass-user > >> > >> > > > >
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