[GRASS-user] strange result of v.overlay in 6.4

GRASS GRASS user
1

Dear Grass users,
I have verified this strange behaviour:

I have two layers:

A has 50 areas "grouped" in a single isle
B has 30 small areas that in part overlap with the boundaries of the A
isle

I have created a new layer C from A and B: A not B = C

Then C was edited by hands (by others using proprietary software)

I finally performed a new cut between C and B: C not B = D

the layer D was correctly created where C was overlapping B (due to the
hands editing) but where the boundary of C was maintained (not edited,
hence perfectly corresponding to the B boundary) the layer D lost the
boundary.

anyone has got a similar problem?

many thanks

Ivan

--
Ti prego di cercare di non inviarmi files .dwg, .doc, .xls, .ppt.
Preferisco formati liberi.
Please try to avoid to send me .dwg, .doc, .xls, .ppt files.
I prefer free formats.
http://it.wikipedia.org/wiki/Formato_aperto
http://en.wikipedia.org/wiki/Open_format

Ivan Marchesini
Perugia (Italy)
Socio fondatore GFOSS "Geospatial Free and Open Source Software" http://www.gfoss.it
e-mail: ivan.marchesini@irpi.cnr.it
        ivan.marchesini@gmail.com
fax (mailfax): +39 1782092534
jabber: geoivan73@jabber.org
skype: geoivan73

2

Hi Ivan,

On Mon, Jul 4, 2011 at 4:03 PM, ivan marchesini
<ivan.marchesini@gmail.com> wrote:

Dear Grass users,
I have verified this strange behaviour:

which GRASS version on which OS?
Latest and greatest stable (i.e. 6.4?)

I have two layers:

A has 50 areas "grouped" in a single isle
B has 30 small areas that in part overlap with the boundaries of the A
isle

I have created a new layer C from A and B: A not B = C

...

please consider to put a screenshot somewhere. Even better, the
data or a reproducible example.

Markus

3

Hi Markus

which GRASS version on which OS?
Latest and greatest stable (i.e. 6.4?)

the release was 6.4 stable

please consider to put a screenshot somewhere. Even better, the
data or a reproducible example.

yes...
you are right..
I can't show my data but I can try to generate some synthetic data..

ciao

Ivan

Markus

--
Ti prego di cercare di non inviarmi files .dwg, .doc, .xls, .ppt.
Preferisco formati liberi.
Please try to avoid to send me .dwg, .doc, .xls, .ppt files.
I prefer free formats.
http://it.wikipedia.org/wiki/Formato_aperto
http://en.wikipedia.org/wiki/Open_format

Ivan Marchesini
Perugia (Italy)
Socio fondatore GFOSS "Geospatial Free and Open Source Software" http://www.gfoss.it
e-mail: ivan.marchesini@irpi.cnr.it
        ivan.marchesini@gmail.com
fax (mailfax): +39 1782092534
jabber: geoivan73@jabber.org
skype: geoivan73