[GRASS-dev] Re: [GRASS-user] v.clean tool=prune - 'thresh' interpreted wrong?

Maciej Sieczka tutey at o2.pl
Tue Oct 3 08:56:18 EDT 2006

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?

Moritz just supposes but he is not sure. And if you look into my
original email you'll that he's wrong:

1. a *straight* line, consisted of 4 vertices, at regular intervals of
2. thresh>0.03 prunes all vertices (besides the nodes of course)
3. thresh<=0.03 prunes none

Then Moritz's idea is wrong.

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


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