[GRASS-user] multiple polygons with same cat

Markus Metz markus.metz.giswork at gmail.com
Tue Nov 26 07:48:21 PST 2013

On Tue, Nov 26, 2013 at 4:34 PM, Dave Roberts
<dvrbts at ecology.msu.montana.edu> wrote:
>> I would suggest to run
>> v.category inp=geo type=centroid out=new_geo op=add layer=2 --o
> Thanks Markus!  Now I'm getting somewhere.  v.info shows geo and new_geo in
> perfect correspondence for areas, islands, boundaries, etc.
> d.what.vect shows new_geo with the original data in layer 1 and the new data
> in layer 2.  v.to.db successfully transferred the centroids (coor) and area
> to layer 2.  However, I still don't see how to get the surficial geology
> column (surgeo) out of layer 1 into layer 2 without a join item.  I know I'm
> missing something simple, but v.to.db just seems to allow a restricted set
> of values for option.

v.to.db map=new_geo layer=2 column=surgeo option=query qlayer=1 qcolumn=surgeo

In this example, the column surgeo in layer 2 must exist and must be
of the same type like the column surgeo in layer 1.

Markus M

> Thanks, Dave
> --
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> David W. Roberts                                     office 406-994-4548
> Professor and Head                                      FAX 406-994-3190
> Department of Ecology                         email droberts at montana.edu
> Montana State University
> Bozeman, MT 59717-3460

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