[GRASS-user] How to link or combine adjacent vector lines

Hamish hamish_b at yahoo.com
Mon Feb 13 06:06:13 EST 2012

Moritz wrote:
> With options first and multi v.build.polylines just copies
> the attribute tables as is, i.e. it does not delete any
> lines for which there are no more category values in the
> vector file.
> To create an attribute table that corresponds to the current
> vector amp with the following steps (supposing that the
> vector map is called river_poly):
> db.copy from_table=river_poly to_table=river_bak # create
> backup of existing table
> v.db.connect -d river_poly # erase line between vector map
> and table river_poly
> db.droptable river_poly # erase table river_poly
> v.db.addtable river_poly # create new table for vector map
> river_poly
> If you do all this using an SQL backend (e.g. SQLite or
> PostgreSQL), you can then use v.db.join to join any
> attributes from the original table river_bak to the new
> table river_poly.

would 'v.extract list=1-9999999' also work?


More information about the grass-user mailing list