[GRASS-user] voronoi for polygons

[Martin Wegmann]

Hello, 

I want to calculate voronoi areas for polygons, but I am stuck in 
the "query-part".

using spearfish data I did:

v.extract input=fields at PERMANENT output=fields_extract list=41,36,46,21          

v.to.points input=fields_extract output=fields_extract_points type=boundary      

v.voronoi input=fields_extract_points output=fields_extract_points_voron        


now I wanted to 
- group all voronoi polygons which belong to points of one polygon (GIS query 
overlap)
- calculate area of merged voronoi polygons and assign them to each original 
polygon

but:

v.select operator=overlap gives:

v.select binput=fields_extract_points_voron_clean ainput=fields_extract_clean 
atype=area btype=area output=test operator=overlap
Processing ainput areas ...
 100%
Writing attributes ...
Layer 1
v.select complete.
Building topology ...
0 primitives registered
0 areas built
0 isles built
Attaching islands:
Attaching centroids: Topology was built.
Number of nodes     :   0
Number of primitives:   0
Number of points    :   0
Number of lines     :   0
Number of boundaries:   0
Number of centroids :   0
Number of areas     :   0
Number of isles     :   0

anything wrong with the command?
I did it as well without b/atype=area but same result. 

The problem how to calculate areas is not yet tackled ,-)

I appreciate any hint, Martin