Hi all!
I try to vectorize a thinned (r.thin) raster map with r.to.vect. After that I
build the topology and create polygons with v.build. This works fine for small
regions, but if I choose a larger one the vectorisation is not finished
properly. It seems like r.to.vect starts at the top of the region and finishes
if a certain value of vetices was made. I can visualise the result, but I can't
built the topology with this vector (ERROR: Cannot open old vector
mwin_vector1@schlesi on level 2).
I zoomed into the extent of the unfinished vector and tryed again:
Building topology ...
42238 primitives registered
Building areas: 100%
0 areas built
0 isles built
Attaching islands:
Attaching centroids: 100%
Topology was built.
Number of nodes : 37573
Number of primitives: 42238
Number of points : 0
Number of lines : 42238
Number of boundaries: 0
Number of centroids : 0
Number of areas : 0
Number of isles : 0
Is there a limit of primitives around 42238 in the vector format?
Is it possible to handle larger vectors?
thank you
Martin
________________________________________________________________________________
hang loose!
Hi Martin,
On Wed, Jul 13, 2005 at 02:23:09PM +0200, Martin Rutzinger wrote:
Hi all!
I try to vectorize a thinned (r.thin) raster map with r.to.vect. After that I
build the topology and create polygons
Question: why do you run r.thin if you want polygons?
with v.build.
There is no need to run v.build, this is done by r.to.vect.
If not, your GRASS version is probably very old?
Perhaps you try without r.thin (which is used from *line* thinning).
For me it worked well so far.
Markus
This works fine for small
regions, but if I choose a larger one the vectorisation is not finished
properly. It seems like r.to.vect starts at the top of the region and finishes
if a certain value of vetices was made. I can visualise the result, but I can't
built the topology with this vector (ERROR: Cannot open old vector
mwin_vector1@schlesi on level 2).
I zoomed into the extent of the unfinished vector and tryed again:
Building topology ...
42238 primitives registered
Building areas: 100%
0 areas built
0 isles built
Attaching islands:
Attaching centroids: 100%
Topology was built.
Number of nodes : 37573
Number of primitives: 42238
Number of points : 0
Number of lines : 42238
Number of boundaries: 0
Number of centroids : 0
Number of areas : 0
Number of isles : 0
Is there a limit of primitives around 42238 in the vector format?
Is it possible to handle larger vectors?
thank you
Martin
________________________________________________________________________________
hang loose!
--
Markus Neteler <neteler itc it> http://mpa.itc.it
ITC-irst - Centro per la Ricerca Scientifica e Tecnologica
MPBA - Predictive Models for Biol. & Environ. Data Analysis
Via Sommarive, 18 - 38050 Povo (Trento), Italy