[GRASS-dev] v.extracy fails for type=boundary

GRASS GRASS developer
1

Dears,

I get something unexpected using type=boundary with `v.external`:

v.extract input=european_grid_10k_boundaries out=test type=boundary --v --o
Using native format
Extracting features...
 100%
Building topology for vector map <test@PERMANENT>...
Registering primitives...
0 primitives registered
0 vertices registered
Topology was built
Number of nodes: 0
Number of primitives: 0
Number of points: 0
Number of lines: 0
Number of boundaries: 0
Number of centroids: 0
Number of areas: 0
Number of isles: 0
Writing attributes...

I tried this in both 7.4 and trunk.

The map does have boundaries,

v.info -t european_grid_10k_boundaries
nodes=253
points=0
lines=0
boundaries=422
centroids=177
areas=177
islands=8
primitives=599
map3d=0

I can draw the boundaries on-screen using `d.vect type=boundary`.

The vector map is small, so I have attached it here-in, in case someone
can have a quick look.

Thank you, Nikos

(attachments)

european_grid_10k_boundaries.grasspack (29 KB)

2

* Nikos Alexandris <nik@nikosalexandris.net> [2018-05-04 16:09:38 +0200]:

Dears,

I get something unexpected using type=boundary with `v.external`:

It's only `v.extract`, `v.external` has nothing to do with here. Sorry.

[..]

Nikos

3

On Fri, May 4, 2018 at 4:09 PM, Nikos Alexandris <nik@nikosalexandris.net> wrote:

Dears,

I get something unexpected using type=boundary with v.external:

v.extract input=european_grid_10k_boundaries out=test type=boundary --v --o
Using native format
Extracting features...
100%
Building topology for vector map <test@PERMANENT>...
Registering primitives...
0 primitives registered
0 vertices registered
Topology was built
Number of nodes: 0
Number of primitives: 0
Number of points: 0
Number of lines: 0
Number of boundaries: 0
Number of centroids: 0
Number of areas: 0
Number of isles: 0
Writing attributes...

The default answer for the layer option of v.extract is 1, i.e. only features with a category in layer 1 will be extracted. If you want to extract all features of a given type, use e.g. v.extract layer=-1 type=boundary.

Markus M

I tried this in both 7.4 and trunk.

The map does have boundaries,

[v.info](http://v.info) -t european_grid_10k_boundaries
nodes=253
points=0
lines=0
boundaries=422
centroids=177
areas=177
islands=8
primitives=599
map3d=0

I can draw the boundaries on-screen using d.vect type=boundary.

The vector map is small, so I have attached it here-in, in case someone
can have a quick look.

Thank you, Nikos

grass-dev mailing list
grass-dev@lists.osgeo.org
https://lists.osgeo.org/mailman/listinfo/grass-dev

4

* Markus Metz <markus.metz.giswork@gmail.com> [2018-05-04 16:41:59 +0200]:

On Fri, May 4, 2018 at 4:09 PM, Nikos Alexandris <nik@nikosalexandris.net>
wrote:

Dears,

I get something unexpected using type=boundary with `v.external`:

v.extract input=european_grid_10k_boundaries out=test type=boundary --v

–o

Using native format
Extracting features…
100%
Building topology for vector map test@PERMANENT…
Registering primitives…
0 primitives registered
0 vertices registered
Topology was built
Number of nodes: 0
Number of primitives: 0
Number of points: 0
Number of lines: 0
Number of boundaries: 0
Number of centroids: 0
Number of areas: 0
Number of isles: 0
Writing attributes…

The default answer for the layer option of v.extract is 1, i.e. only
features with a category in layer 1 will be extracted. If you want to
extract all features of a given type, use e.g. v.extract layer=-1
type=boundary.

Markus M

Understood, it works. It's also in the NOTES of the manual, which I
obviously missed to read carefully.

Thank you Markus