[GRASS-user] update cat column in vector data set

[Stefan Luedtke]

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?

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 <sluedtke at gfz-potsdam.de> 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
> > grass-user at lists.osgeo.org
> > http://lists.osgeo.org/mailman/listinfo/grass-user
> >
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/grass-user/attachments/20120816/c32c590c/attachment.html>