[GRASS5] [bug #4247] (grass) v.build.polylines: fails to build a polyline out of a closed boundary

[Request Tracker]

this bug's URL: http://intevation.de/rt/webrt?serial_num=4247
-------------------------------------------------------------------------

Subject: v.build.polylines: fails to build a polyline out of a closed boundary

Platform: GNU/Linux/x86
grass obtained from: CVS
grass binary for platform: Compiled from Sources
GRASS Version: 2006-04-05

If v.build.polylines in run on a topologicaly clean, self-closed boundary, the output will be an "incorrect bondary", twice that long as the input.

See screenshots from v.digit:

input:
http://www.biol.uni.wroc.pl/sieczka/udostepnione/grass/poly/parcel.png

v.build.polylines output "incorrect boundary":
http://www.biol.uni.wroc.pl/sieczka/udostepnione/grass/poly/parcel_poly.png

after editing the output the problem becomes visible:
http://www.biol.uni.wroc.pl/sieczka/udostepnione/grass/poly/parcel_poly_edited.png



Details:

### See that the input is clean:

$ v.build parcel
Building topology ...
1 primitives registered
Building areas:  100%
1 areas built
1 isles built
Attaching islands:  100%
Attaching centroids:  100%
Topology was built.
Number of nodes     :   1
Number of primitives:   1
Number of points    :   0
Number of lines     :   0
Number of boundaries:   1
Number of centroids :   0
Number of areas     :   1
Number of isles     :   1
Number of areas without centroid :   1



### But after processing with the v.build.polylines it is not (an incorrect
### boundary is created):

$ v.build.polylines input=parcel output=parcel_poly
reating new map parcel_poly 
The number of lines in the binary map is 1

Polyline 0: start line = 1 
The number of polylines in the output map is 1 
Building topology ...
Registering lines: 
1 primitives registered      
Building areas: 


0 areas built      
0 isles built
Attaching islands: 
Attaching centroids: 

Topology was built.
Number of nodes     :   1
Number of primitives:   1
Number of points    :   0
Number of lines     :   0
Number of boundaries:   1
Number of centroids :   0
Number of areas     :   0
Number of isles     :   0
Number of incorrect boundaries   :   1



Grass location with forementioned vectors:
http://www.biol.uni.wroc.pl/sieczka/udostepnione/grass/poly/poly.tar.bz2

Maciek


-------------------------------------------- Managed by Request Tracker