[GRASS-dev] the function of v.buffer `minordistance' option

[Moritz Lennert]

On 04/06/14 20:42, Maciej Sieczka wrote:
> W dniu 04.06.2014 14:53, Moritz Lennert pisze:
>> On 03/06/14 19:59, Maciej Sieczka wrote:
>
>>> Anybody knows what is the v.buffer's `minordistance' option supposed
>>> to do?
>>>
>>> The manual is not verbose about that, but as I understand it, together
>>> with `distance', it should allow to create a buffer with different
>>> extent along the minor and major axis, considering the specified `angle'
>>> of their rotation.
>>>
>>> But none of the options works as that - the buffer size always equals
>>> the `distance', and the other 2 options make no difference if used or
>>> not an set to what.
>>>
>>> BTW, it seems that -s, -c flags also don't have any effect on the
>>> output.
>>>
>>> Did I get it wrong or maybe there's something broken?
>
>> In NC dataset:
>>
>> v.buffer schools_wake out=testbuf distance=500 minordistance=250
>>
>> gives me the attached buffers. Everything seems to work fine here...
>>
>> Could you be more specific about what exactly is not working for you ?
>
> Right, looks fine for points input. Not so for areas input though, e.g:
>
> $ v.buffer testbuf out=testbuf2 distance=500 minordistance=250
>
> v.buffer in the latter case does not honor minordistance and uses
> distance for both axes, while I would expect it to behave the way it
> does for points input. Am I expecting something which is not implemented
> maybe?

For me this is more of a conceptual problem: how can you define a major 
and minor axis for buffers of polygons ?

Moritz