[GRASS-user] updating vector attributes for separate islands

GRASS GRASS user
1

Hi,

I imported a shapefile of provinces in grass. The shapefile has
around 84 provinces composed of different islands. The attribute
table contains only 84 rows corresponding to 84 provinces. I used
v.clean bpol tool to topologically clean the vectors. Then used
v.db.droptable and add a new a table to add island names for each
polygon.

The new table created still contain 84 rows and when I edit an island
centroid the island name is also added to the other polygon covered by
the same province.

--
cheers,
maning
------------------------------------------------------
"Freedom is still the most radical idea of all" -N.Branden
wiki: http://esambale.wikispaces.com/
blog: http://epsg4253.wordpress.com/
------------------------------------------------------

2

maning sambale wrote:

Hi,

I imported a shapefile of provinces in grass. The shapefile has
around 84 provinces composed of different islands. The attribute
table contains only 84 rows corresponding to 84 provinces. I used
v.clean bpol tool to topologically clean the vectors. Then used
v.db.droptable and add a new a table to add island names for each
polygon.

The new table created still contain 84 rows and when I edit an island
centroid the island name is also added to the other polygon covered by
the same province.
  

They all have the same category number, so if you add a row to the attribute table, all polygons with that category number will use that row. You can set new categories for each polygon separately with v.category in a new layer 2, then add a table for layer 2 and edit the attribute table.

Markus M

3

Thanks! it's working now

On 8/17/09, Markus Metz <markus.metz.giswork@googlemail.com> wrote:

maning sambale wrote:

Hi,

I imported a shapefile of provinces in grass. The shapefile has
around 84 provinces composed of different islands. The attribute
table contains only 84 rows corresponding to 84 provinces. I used
v.clean bpol tool to topologically clean the vectors. Then used
v.db.droptable and add a new a table to add island names for each
polygon.

The new table created still contain 84 rows and when I edit an island
centroid the island name is also added to the other polygon covered by
the same province.

They all have the same category number, so if you add a row to the
attribute table, all polygons with that category number will use that
row. You can set new categories for each polygon separately with
v.category in a new layer 2, then add a table for layer 2 and edit the
attribute table.

Markus M

--
cheers,
maning
------------------------------------------------------
"Freedom is still the most radical idea of all" -N.Branden
wiki: http://esambale.wikispaces.com/
blog: http://epsg4253.wordpress.com/
------------------------------------------------------