[GRASS-dev] v.clean threshold value unit for 'prune'

[Markus Metz]

On Thu, Jan 26, 2017 at 11:15 AM, Paulo van Breugel <p.vanbreugel at gmail.com>
wrote:
>
>
>
> On 26-01-17 11:03, Markus Metz wrote:
>
>
>
> On Thu, Jan 26, 2017 at 10:51 AM, Paulo van Breugel <
p.vanbreugel at gmail.com> wrote:
> >
> > Hi
> >
> > I am using the v.clean tool with the option "prune". According to the
manual, threshold values have to be in map units. I am using this with a
latlon map with vertices as close as 0.0001 degrees. However, v.clean only
removes vertices at threshold values of about 50 or up. This seems to
suggest that the tools assumes threshold values are in meters?
>
> The prune tool of v.clean never really worked. Please use v.generalize
instead.
>
>
> OK, will do. Still the question remains whether this is a bug, an error
in the manual page (i.e., threshold values are not in mapping units, but in
meters like for the rmarea) , or I am doing something wrong (note that it
seems to work fine if one assumed threshold values have to be in meters).
If a bug or error in the manual page, I can create a ticket.

It's a bug in the code [0], the algorithm is not working properly. There is
v.generalize, therefore I recommend to remove the prune tool from v.clean.

Markus M

[0]
https://trac.osgeo.org/grass/browser/grass/trunk/lib/vector/diglib/prune.c
>
>
>
> Markus M
>
> >
> > Best wishes,
> >
> > Paulo
> >
> > _______________________________________________
> > grass-dev mailing list
> > grass-dev at lists.osgeo.org
> > https://lists.osgeo.org/mailman/listinfo/grass-dev
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/grass-dev/attachments/20170126/4d4b5d61/attachment.html>