[GRASS-user] problems with v.to.rast?

GRASS GRASS user
1

Hello, I just converted a vector map from boundaries to lines, and
then tried to convert it to a raster, but unsuccessfully.

here are my outputs:

v.type_wrapper.sh input=soilmu@workshop output=soilmu_lin
'type=boundary to line' --overwrite

-- Vector map <soilmu_lin> already exists and will be overwritten
Building topology for vector map <soilmu_lin>...
53 primitives registered

3353 vertices registered

Building areas...
0 areas built
0 isles built
Attaching islands...
Attaching centroids...
Number of nodes: 43
Number of primitives: 53
Number of points: 0
Number of lines: 36
Number of boundaries: 0
Number of centroids: 17
Number of areas: 0
Number of isles: 0
Number of centroids outside area: 17
Registering primitives...

v.to.rast input=soilmu_lin@workshop output=soilmu_lin use=val
type=line layer=1 value=1 rows=4096 --overwrite
Loading data...
Reading features...
Writing raster map...
Converted areas: 0 of 0
Converted points/lines: 0 of 36
v.to.rast complete.

I'm quite lost here. Converting to raster before changing from
boundaries to lines doesn't work, as I want only the outlines of the
polygons.

Thanks for any hint.

(PS. latest SVN, Linux)

Carlos

Carlos Henrique Grohmann - Geologist D.Sc.
a.k.a. Guano - Linux User #89721
ResearcherID: A-9030-2008

http://digitalelevation.blogspot.com

http://www.igc.usp.br/pessoais/guano
_________________
Can’t stop the signal.

2

Carlos wrote:

Hello, I just converted a vector map
from boundaries to lines, and
then tried to convert it to a raster, but unsuccessfully.

boundaries typically do not have cat numbers assigned. only features
with cat numbers will be considered by v.to.rast. Use v.category to
add cat numbers to features.

H

3

Yes, using v.category after v.types works. It would be nice if
category were added automatically, though.

cheers

Carlos

On Mon, Aug 24, 2009 at 14:50, Hamish<hamish_b@yahoo.com> wrote:

Carlos wrote:

Hello, I just converted a vector map
from boundaries to lines, and
then tried to convert it to a raster, but unsuccessfully.

boundaries typically do not have cat numbers assigned. only features
with cat numbers will be considered by v.to.rast. Use v.category to
add cat numbers to features.

H

--
Carlos Henrique Grohmann - Geologist D.Sc.
a.k.a. Guano - Linux User #89721
ResearcherID: A-9030-2008

http://digitalelevation.blogspot.com

http://www.igc.usp.br/pessoais/guano
_________________
Can’t stop the signal.

4

Carlos wrote:

Yes, using v.category after v.types works. It would be nice if
category were added automatically, though.

please file a wish (enhancement) in the trac system.

it should not be done by default (often it is not what you want
to happen), but v.type could have an optional flag which would
do that for you as it's a common need.

regards,
Hamish