[GRASS-user] Fwd: Re: [Qgis-developer] Sextante: v.buffer angle does not work

[Moritz Lennert]

On 30/05/12 18:44, Paolo Cavallini wrote:
> FYI.
> Thanks.
>
> -------- Messaggio originale --------
> Oggetto: Re: [Qgis-developer] Sextante: v.buffer angle does not work
> Data: Wed, 30 May 2012 18:33:19 +0200
> Mittente: Victor Olaya<volayaf at gmail.com>
> A: cavallini at faunalia.it
> CC: qgis-developer<qgis-developer at lists.osgeo.org>
>
> mmmm, I had splitted it, and in fact this algorithm just calls the
> angle option, but it still complains
>
> This is your command line
>
> v.buffer input=tmp1338388935286 angle=90 tolerance=0.01 -s -c
> output=output --overwrite
>
> and it says
>
> ERRORE: Select a buffer distance/minordistance/angle or column, but not
>         both.
>
> But it's only passing an angle, not any of the other options!!!. Or
> you are not supposed to use tolerance with the angle option?


Actually, the relevant part of the code is this:
	
if (((dista_opt->answer || buffer_opt->answer) && bufcol_opt->answer) ||
    (!(dista_opt->answer || buffer_opt->answer || bufcol_opt->answer)))
         G_fatal_error(_("Select a buffer distance/minordistance/angle "
	                        "or column, but not both."));

which means that you need either a buffer distance or a buffer column, 
but not neither or both of these. I guess the 
"distance/minordistance/angle" part was meant to signal that distance 
could be combined with minordistance and or angle, but I agree that the 
message is not very clear in that way. I think it should rather read 
something like this:

"You must indicate either a buffer distance or column, but not both."

An angle on its own could not define a buffer, so it would be useless.

Moritz