[GRASS-user] Using v.edit to snap dangling lines

[Martin Landa]

Hi,

2008/2/27, David Mahoney <mahoneyd at unbc.ca>:

I rewrote today query=dangle part of v.edit to use the algorithm of
v.clean tool=rmdangle|chdangle (lib/vector/Vlib/dangles.c). I am not
sure if it can solve your problem. I also added possibility to define
different threshold values for coordinates selection, snapping and
querying.

> I've been trying to use v.edit to snap dangling lines after patching
>  together a bunch of maps. However, the query=dangle option does not
>  seem to work. I've tried:
>  v.edit map=roads tool=select query=dangle thresh=0
>  v.edit map=roads tool=select query=dangle thresh=-0
>  v.edit map=roads tool=select query=dangle thresh=10000
>  v.edit map=roads tool=select query=dangle thresh=-10000

(from Spearfish, selecting dangles shorter then 100 map units)

v.edit map=roads tool=select query=dangle thresh=-1,0,-100 --v
35 of 825 features selected from vector map <roads at PERMANENT>

to snap selected features in threshold 5 map units

$ v.edit map=roads tool=snap query=dangle thresh=-1,5,-100 --v
Threshold value for querying is -100.00
35 of 825 features selected from vector map <roads at PERMANENT>
Threshold value for snapping is 5.00
----------------------------------
All vertices              :   86
Registered points         :   83
Nodes marked as anchor    :   80
Nodes marked to be snapped:    3
Snapped vertices          :    3
New vertices              :    0
----------------------------------

[snip]

>  I'm using GRASS 6.3 cvs (about a month old) on Mac OS X

Hope it helps.

Martin

-- 
Martin Landa <landa.martin gmail.com> * http://gama.fsv.cvut.cz/~landa *