[GRASS-user] using v.line.center

Maciej Sieczka tutey at o2.pl
Fri Jun 6 17:37:58 EDT 2008

Manuel Sangiao pisze:
> Hi all,
> after the reprojection in another mapset I used v.line.center, all
> ok. But, I obtain a new layer without database. The input layer have
> database.

v.line.center does not copy the input vector's table to output vector.

> v.db.connect -p glines1 Vector map <glines1> is connected by: layer
> <2> table <glines1> in database 
> </scratch/manuel/GISDATA//admprojected/manuel/dbf/> through driver
> <dbf> with key <cat>

> I have read that the result layer (pts1) contains the category
> numbers of the input vector line layer.
> Is there a solution?

Yes. As the category numbers are the same, you can:

# given that the name of the v.line.center's input vector is "lines" and
# the output is "points":

# copy the input table:
db.copy from_table=lines to_table=points

# connect the table "points" to vector map "points":
v.db.connect points table=points

Now query (d.what.vect, v.db.select) to check if everything's OK.

Mind that I assume plenty of defaults in the example above - verify your
layer number, key column name etc. Refer to to commands's manuals.


Maciej Sieczka

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