[GRASS-user] Clipping area theme

[Jean-François Moyen]

[GRASS 6.4 windows XP -- accessed mostly via QGis but here I'll be using the
CLI]
[not sure which sub-version of GRASS, I believe the latest one installed two
days ago from OSGeo "package manager"]

My second problem involves clipping vectors. I do have a vector theme
(geological map) with a correct topology, as far as I can tell -- boundaries
and centroids; QGis happily reads it as a polygon theme anyway, without
apparent errors. I can also convert it to a clean raster, etc.

I also have another vector theme, containing only one polygon : my area of
interest.

I want to clip my Geol_map to the extent of the Area; and I try the
following :

> v.overlay ainput=Geol_map atype=area alayer=1 binput=Area btype=area
blayer=0 output=Geol_map_clipped operator=and

The result follows; basically, no polygon nor contour is created...

Thanks for any advice !

JFM
-------------
> v.overlay ainput=Geol_map atype=area alayer=1 binput=Area btype=area
blayer=0 output=Geol_map_clipped operator=and
(.. first lines of the log truncated by command.com, darn, must really
switch to a sensible shell...)
(...) GRASS_INFO_PERCENT: 100


GRASS_INFO_MESSAGE(5356,40): Querying vector map <Area at Brinsley>...
GRASS_INFO_END(5356,40)
GRASS_INFO_PERCENT: 16
(...)
GRASS_INFO_PERCENT: 100

GRASS_INFO_PERCENT: 1
(...)
GRASS_INFO_PERCENT: 100

GRASS_INFO_MESSAGE(5356,41): Writing centroids...
GRASS_INFO_END(5356,41)

GRASS_INFO_MESSAGE(5356,42): Attaching centroids...
GRASS_INFO_END(5356,42)

GRASS_INFO_MESSAGE(5356,43): Building topology for vector map
<Geol_map_clipped>
...
GRASS_INFO_END(5356,43)

GRASS_INFO_MESSAGE(5356,44): Attaching centroids...
GRASS_INFO_END(5356,44)

GRASS_INFO_PERCENT: 1
(...)
GRASS_INFO_PERCENT: 100

GRASS_INFO_MESSAGE(5356,45): Number of nodes: 1365
GRASS_INFO_END(5356,45)

GRASS_INFO_MESSAGE(5356,46): Number of primitives: 2103
GRASS_INFO_END(5356,46)

GRASS_INFO_MESSAGE(5356,47): Number of points: 0
GRASS_INFO_END(5356,47)

GRASS_INFO_MESSAGE(5356,48): Number of lines: 0
GRASS_INFO_END(5356,48)

GRASS_INFO_MESSAGE(5356,49): Number of boundaries: 2103
GRASS_INFO_END(5356,49)

GRASS_INFO_MESSAGE(5356,50): Number of centroids: 0
GRASS_INFO_END(5356,50)

GRASS_INFO_MESSAGE(5356,51): Number of areas: 595
GRASS_INFO_END(5356,51)

GRASS_INFO_MESSAGE(5356,52): Number of isles: 63
GRASS_INFO_END(5356,52)

GRASS_INFO_MESSAGE(5356,53): Number of incorrect boundaries: 4
GRASS_INFO_END(5356,53)

GRASS_INFO_MESSAGE(5356,54): Number of areas without centroid: 595
GRASS_INFO_END(5356,54)

GRASS_INFO_PERCENT: 1
(...)
GRASS_INFO_PERCENT: 100

GRASS_INFO_MESSAGE(5356,55): Rebuilding topology...
GRASS_INFO_END(5356,55)

GRASS_INFO_MESSAGE(5356,56): Building topology for vector map
<Geol_map_clipped>
...
GRASS_INFO_END(5356,56)

GRASS_INFO_MESSAGE(5356,57): Registering primitives...
GRASS_INFO_END(5356,57)

GRASS_INFO_MESSAGE(5356,58): 0 primitives registered
GRASS_INFO_END(5356,58)

GRASS_INFO_MESSAGE(5356,59): 0 vertices registered
GRASS_INFO_END(5356,59)

GRASS_INFO_MESSAGE(5356,60): Building areas...
GRASS_INFO_END(5356,60)

GRASS_INFO_MESSAGE(5356,61): 0 areas built
GRASS_INFO_END(5356,61)

GRASS_INFO_MESSAGE(5356,62): 0 isles built
GRASS_INFO_END(5356,62)

GRASS_INFO_MESSAGE(5356,63): Attaching islands...
GRASS_INFO_END(5356,63)

GRASS_INFO_MESSAGE(5356,64): Attaching centroids...
GRASS_INFO_END(5356,64)

GRASS_INFO_MESSAGE(5356,65): Number of nodes: 0
GRASS_INFO_END(5356,65)

GRASS_INFO_MESSAGE(5356,66): Number of primitives: 0
GRASS_INFO_END(5356,66)

GRASS_INFO_MESSAGE(5356,67): Number of points: 0
GRASS_INFO_END(5356,67)

GRASS_INFO_MESSAGE(5356,68): Number of lines: 0
GRASS_INFO_END(5356,68)

GRASS_INFO_MESSAGE(5356,69): Number of boundaries: 0
GRASS_INFO_END(5356,69)

GRASS_INFO_MESSAGE(5356,70): Number of centroids: 0
GRASS_INFO_END(5356,70)

GRASS_INFO_MESSAGE(5356,71): Number of areas: 0
GRASS_INFO_END(5356,71)

GRASS_INFO_MESSAGE(5356,72): Number of isles: 0
GRASS_INFO_END(5356,72)

GRASS_INFO_MESSAGE(5356,73): v.overlay complete.
GRASS_INFO_END(5356,73)
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