[GRASS-dev] Re: [GRASS-user] v.clean tool=prune
- 'thresh' interpreted wrong?
mlennert at club.worldonline.be
Tue Oct 3 09:21:38 EDT 2006
Markus Neteler wrote:
> On Tue, Oct 03, 2006 at 02:56:18PM +0200, Maciej Sieczka wrote:
>> Markus Neteler wrote:
>>> On Tue, Oct 03, 2006 at 02:23:56PM +0200, Moritz Lennert wrote:
>>>> I would guess that the prune tool prunes all
>>>> "unneccessary" nodes on a straight line, i.e. any node which is not
>>>> necessary to define the line, and this whatever the threshold.
>>>> The threshold only applies in cases of change of direction (i.e. angles).
>>>> Just another example of the need for much more documentation for
>>>> v.clean, including example diagrams like the one for the rmsa tool.
>>> Fully agreed...
>> Agreed regarding what?
> ... regarding that more documentation is needed.
>> And I need to know exactly how the thresh in prune works, as I'm using
>> it for my work. The result will be a script that I'm going to publish.
>> Please - if anybody knows, tell me. I'd love to update the manual
> Apparently it can be only reverse engineered (luckily it's FOSS).
> I was not too happy with my attempts to use the prune algorithm,
> I don't think that it works reasonable well.
> But this is an old story:
> The first mail indicates that the problem is known and wasn't
> resolved so far. Time to switch to another algorithm :-)
Michel's changes date from 1998 and were apparently written for 4.2.1,
so there was change since then. Don't know if that resolved the problem
though... Nor which algorithm is better.
More information about the grass-dev