[GRASSLIST:4410] v.out.ogr topology?

GRASS GRASS user
1

[5.7]

When exporting areas (with labeled centroids) from 5.7, then linking the
shape file back in with v.external, I see that what were holes in the
area are now new areas with their own centroids.

What's the correct way to export areas with holes into a shape file,
while keeping the holes as holes?

currently using:
  v.out.ogr dsn=. type=area in=some_area layer=some_area

thanks,
Hamish

2

-c

Radim

On Friday 24 September 2004 05:33, Hamish wrote:

[5.7]

When exporting areas (with labeled centroids) from 5.7, then linking the
shape file back in with v.external, I see that what were holes in the
area are now new areas with their own centroids.

What's the correct way to export areas with holes into a shape file,
while keeping the holes as holes?

currently using:
  v.out.ogr dsn=. type=area in=some_area layer=some_area

thanks,
Hamish

3

> [5.7]
>
> When exporting areas (with labeled centroids) from 5.7, then linking
> the shape file back in with v.external, I see that what were holes
> in the area are now new areas with their own centroids.
>
> What's the correct way to export areas with holes into a shape file,
> while keeping the holes as holes?
>
> currently using:
> v.out.ogr dsn=. type=area in=some_area layer=some_area

Radim:
-c

Yes, that works. Thanks.

Next issue:

after linking the resultant shape file back in with v.external, the
categories are labeled starting with 0 instead of 1. This caught me out
when doing 'd.vect cat=1-1000' and the first area was missing. (the
linked table has a "cat" column which has the original (correct) cat
number but is unused.
Is this a bug or a feature?

Hamish

4

after linking the resultant shape file back in with v.external, the
categories are labeled starting with 0 instead of 1. This caught me
out when doing 'd.vect cat=1-1000' and the first area was missing.
(the linked table has a "cat" column which has the original (correct)
cat number but is unused.
Is this a bug or a feature?

This is the "id" column created by v.out.ogr.

perhaps v.external could get category info from the "cat" column if one
exists? shrug.

Hamish