[GRASS-user] bug or buffer for polygons impossible ?

Hello,
I try to create a buffer around a polygon with the following commande:

v.buffer input=... output=.... distance=10

This creates the buffer visible in the following picture:
http://dl.lyon.cemagref.fr/get?k=yQnyOaVULt3QQmOSSVa
Why is the buffer not uniform? (Regarding the upper left corner, one corner misses).

http://dl.lyon.cemagref.fr/get?k=IF0oiMFkqyVC9L9SCeA
http://dl.lyon.cemagref.fr/get?k=zCtzYAQDCXMYdz6TUoE
http://dl.lyon.cemagref.fr/get?k=IWMhOGONCrDQevnMRck
Other errors...

Is this a bug in the v.buffer function, or do I try to use the buffer function on polygons, which is not possible?
I'm working on WinGRASS 6.4.
Many thanks for any help!

Yvan

Hello,
I try to create a buffer around a polygon with the following commande:
v.buffer input=… output=… distance=10

I’am using the windows osgeo4w version and the buffer around a polygon works fine even for complex polygons.
By the images it looks like you have overlaping or duplicated boundaries.

Can you send the full command and a image of the vector editing of these polygons?

Regards.
Pablo.


Faça compras on-line com mais segurança. Instale grátis o Internet Explorer 8.

Yvan Paillé wrote:

I try to create a buffer around a polygon with the
following commande:

v.buffer input=... output=.... distance=10

This creates the buffer visible in the following picture:
http://dl.lyon.cemagref.fr/get?k=yQnyOaVULt3QQmOSSVa
Why is the buffer not uniform? (Regarding the upper left
corner, one corner misses).

http://dl.lyon.cemagref.fr/get?k=IF0oiMFkqyVC9L9SCeA
http://dl.lyon.cemagref.fr/get?k=zCtzYAQDCXMYdz6TUoE
http://dl.lyon.cemagref.fr/get?k=IWMhOGONCrDQevnMRck
Other errors...

Is this a bug in the v.buffer function, or do I try to use
the buffer function on polygons, which is not possible?
I'm working on WinGRASS 6.4.
Many thanks for any help!

it's a bug. see https://trac.osgeo.org/grass/ticket/90

usually the effect is minor but maybe it is much worse on MS Windows??
(I haven't tried)

Hamish