I’m writing since I need to clean a line vector (road network) removing all the line segments not connected to other segments. I guess that I need to remove all the segment that have valence = 0.
I need to remove them to perform a network distance analysis avoiding the issue of unreachable nodes.
Is there any way to do it?
Thanks for any help
Matteo
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Matteo Marcantonio
PhD Candidate GIS & Remote Sensing Fondazione Edmund Mach (FEM) - Research & Innovation Centre (CRI)
On Tue, Nov 4, 2014 at 11:17 PM, matteo marcantonio
<matteo.marcantonio@fmach.it> wrote:
Hello list,
I'm writing since I need to clean a line vector (road network) removing all
the line segments not connected to other segments. I guess that I need to
remove all the segment that have valence = 0.
I need to remove them to perform a network distance analysis avoiding the
issue of unreachable nodes.
Is there any way to do it?
You could use v.net.alloc with one node and then extract the allocated
network. This will automatically discard all lines not connected to
this node.
Markus M
Thanks for any help
Matteo
--
--
Matteo Marcantonio
PhD Candidate
GIS & Remote Sensing
Fondazione Edmund Mach (FEM) - Research & Innovation Centre (CRI)
I’m writing since I need to clean a line vector (road network) removing all
the line segments not connected to other segments. I guess that I need to
remove all the segment that have valence = 0.
I need to remove them to perform a network distance analysis avoiding the
issue of unreachable nodes.
Is there any way to do it?
You could use v.net.alloc with one node and then extract the allocated
network. This will automatically discard all lines not connected to
this node.
This is a good suggestion but it is not exactly what I need.
I need to connect all my nodes to the main road network avoiding that a node is connected to a ‘dead road segment’ (being unreachable by v.net.distance).
So I need to clean my road network, removing all the ‘isolated road segment’ (or 'valence=0).
Any suggestion?
Markus M
Thanks for any help
Matteo
Matteo
–
Matteo Marcantonio
PhD Candidate
GIS & Remote Sensing
Fondazione Edmund Mach (FEM) - Research & Innovation Centre (CRI)
On Wed, Nov 5, 2014 at 9:59 AM, Markus Metz
<markus.metz.giswork@gmail.com> wrote:
On Tue, Nov 4, 2014 at 11:17 PM, matteo marcantonio
<matteo.marcantonio@fmach.it> wrote:
Hello list,
I'm writing since I need to clean a line vector (road network) removing all
the line segments not connected to other segments. I guess that I need to
remove all the segment that have valence = 0.
I need to remove them to perform a network distance analysis avoiding the
issue of unreachable nodes.
Is there any way to do it?
You could use v.net.alloc with one node and then extract the allocated
network. This will automatically discard all lines not connected to
this node.
Sounds good - but isn't it that v.net.alloc requires at least two
nodes? Of course I could then merge the two resulting subnets which do
no longer contain the unconnected vector lines.