[GRASS-user] v.out.ascii with vector created by v.net.allpairs

[Markus Metz]

On Thu, Jan 31, 2013 at 11:00 AM, Johannes Radinger
<johannesradinger at gmail.com> wrote:
>>
>> You could
>> 1) create new categories in a new layer with v.category
>> 2) add columns from_cat, to_cat to the new layer
>> 3) upload values by assigning from_cat (new layer) = cat (old layer)
>> and to_cat (new layer) = to_cat (old layer)
>>
>
> That sounds like a good idea, but somehow I fail. What I did was:
> 1) create a new attribute table/layer for the vector point map with
> v.db.addtable map="orig" table="new_table" layer=2
>
> 2) The second layer does have a cat column but without any entries
> yet. So far so good
> So I tried as you said to create new unique categories in this new layer with
> v.category input=orig output=new layer=2
>
> But here I get following error:
> Copying attribute table(s)...
> DBMI-SQLite driver error:
> Error in sqlite3_step():
> indexed columns are not unique
> WARNING: Unable to create index for table <new_1>, key <cat>
>
Try to start everything again anew with dbf as default database
connection. This should avoid the index problem because dbf does not
support indexing.

> v.category copies the map to a new one and tries to connect both
> attribute tables....but there are no unique cat values in table/layer 1
>
> Is it possible to update layer to without copying the whole map with
> both layers (v.category)
> to get new cats in layer 2...

But you need the attribute table for layer 1 in order to create the
desired attribute table for layer 2?

HTH

Markus M

>
> Anyway it seems the easiest way is to just fetch the entries with
> db.select as Markus said before.
> ...or to use GRASS7 :)
>
> /johannes