[GRASS-user] Collapsing many layers into 1

[Neil Godfrey]

My problem is a little different.  I have just one map, but many layers.
I want to get one map, with just one layer.

On Tue, 2008-01-22 at 10:58 +0100, Martin Landa wrote:
> Hi,
> 
> 2008/1/22, Neil Godfrey <neil at thegodfreys.net>:
> > The census 2000 administrative boundaries are shapefiles, where every
> > county is a separate file.  So v.in.ogr creates a layer for every
> > county.  So for example, I get 83 layers for the 83 counties in
> > Michigan, which correspond to 83 tables, each with just one category.
> >
> > What I want is one layer with 83 categories.  I've had no luck with
> > v.overlay, v.extract, v.patch, etc. because all those tools preserve the
> > layers in the output map.
> >
> > Is there any way to do this?
> 
> If the attribute tables have the same structure (number of columns,
> data types and key column), you can patch maps using
> 
> v.patch -e in=`g.mlist vect pat='con*' out=con_patch
> v.clean in=con_patch out=con_clean tool=snap,break,rmdupl thresh=[value]
> 
> ?
> 
> Martin
>