[GRASS-dev] Re: [GRASS-user] v.buffer creates artefact - bug?

[Moritz Lennert]

On 30/01/07 22:48, Maciej Sieczka wrote:

> v.buffer was fixed a lot in last months, mainly by Hamish. Many thanks
> to him! And it works mostly OK these days. I'm saying almost - because
> there is still a strange error that I can reproduce always and Hamish
> cannot, although we are using exactly same data. We asked GRASS Folks
> to try to reproduce that too, but there was no feedback. So let me ask
> you All again:
> 
> 1. Grab the location:
> http://kufaya.googlepages.com/vbuffer_issue.tar.bz2
> 
> There is only one vector 'ditch_1205' in mapset 'ditch'. Please buffer
> it with:
> v.buffer in=ditch_1205 out=ditch_1205_buf4 type=area buffer=4
> 
> 2. Please drop a line in this thread whether your output looks like
> this (OK, Hamish's case):
> http://kufaya.googlepages.com/ditch_1205_edt_b4.png
> 
> or this (bad, my case):
> http://kufaya.googlepages.com/ditch_1205_b4.png

I get the same (bad) results as you.


> 
> With any thoughts on what is going on here.

Not really, only that there are some other strange elements than the 
centre part:

http://moritz.homelinux.org/grass/ditch_buff_top.jpg
http://moritz.homelinux.org/grass/ditch_buff_bottom.jpg

show that the buffer (in red) cuts through the original area at the top 
and the bottom. AFAIU buffering this is not the expected behaviour.

Moritz