[GRASS-user] Extract subnet from grass vector network based on selected nodes

[Stefan Blumentrath]

Did you try:
v.net.allpairs input=river_network out=river_sampling_subnet where=”node_type=’sampling point’” # You could also use “cats=1-5” or whatever… and maybe also specify arc_column=name arc_backward_column=name as I assume your network is directed, but arc_column options are probably not necessary..

Cheers
Stefan



From: grass-user [mailto:grass-user-bounces at lists.osgeo.org] On Behalf Of Stefan Blumentrath
Sent: onsdag 27. september 2017 13.30
To: Johannes Radinger <johannesradinger at gmail.com>; GRASS user list <grass-user at lists.osgeo.org>
Subject: Re: [GRASS-user] Extract subnet from grass vector network based on selected nodes

Sorry, there is: https://grass.osgeo.org/grass72/manuals/v.net.allpairs.html

From: grass-user [mailto:grass-user-bounces at lists.osgeo.org] On Behalf Of Johannes Radinger
Sent: onsdag 27. september 2017 13.12
To: GRASS user list <grass-user at lists.osgeo.org<mailto:grass-user at lists.osgeo.org>>
Subject: [GRASS-user] Extract subnet from grass vector network based on selected nodes

Hi,

I have a GRASS vector network that represents a river network (with many first order tributaries) and that has additional connected nodes that represent sampling sites.

I'd like to extract a minimum subnetwork of the full network that still connects a set of selected nodes (e.g. identified by their cat). However, network edges (i.e. river segments) that are not necessary to connect the sampling points should be excluded in the new subnetwork. Is there a function or process in GRASS GIS to extract such a subnetwork that fully connects a set of selected nodes?

Cheers,
Johannes
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/grass-user/attachments/20170928/7e213d4f/attachment-0001.html>