GRASS GIS manual: v.net.bridge

Note: A new GRASS GIS stable version has been released: GRASS GIS 7.4, available here.
Updated manual page: here

NAME

v.net.bridge - Computes bridges and articulation points in the network.

KEYWORDS

vector, network, articulation points

SYNOPSIS

v.net.bridge

v.net.bridge --help

v.net.bridge input=name output=name [arc_layer=string] [node_layer=string] [arc_column=name] [arc_backward_column=name] [node_column=string] method=string [--overwrite] [--help] [--verbose] [--quiet] [--ui]

Flags:

--overwrite: Allow output files to overwrite existing files
--help: Print usage summary
--verbose: Verbose module output
--quiet: Quiet module output
--ui: Force launching GUI dialog

Parameters:

input=name [required]: Name of input vector map; Or data source for direct OGR access
output=name [required]: Name for output vector map
arc_layer=string: Arc layer; Vector features can have category values in different layers. This number determines which layer to use. When used with direct OGR access this is the layer name.; Default: 1
node_layer=string: Node layer; Vector features can have category values in different layers. This number determines which layer to use. When used with direct OGR access this is the layer name.; Default: 2
arc_column=name: Arc forward/both direction(s) cost column (number)
arc_backward_column=name: Arc backward direction cost column (number)
node_column=string: Node cost column (number)
method=string [required]: Feature type; Options: bridge, articulation; bridge: Finds bridges; articulation: Finds articulation points

DESCRIPTION
NOTES
EXAMPLES
SEE ALSO
AUTHORS

DESCRIPTION

v.net.bridge finds bridges and articulation points in a network.

NOTES

Bridge in a network is an edge/line whose removal would disconnect the (sub-)network. A node is an articulation point if its removal would disconnect the (sub-)network. For more information and formal definitions check the wikipedia entries: bridge and articulation point.

The output of the module contains the selected features. For method=bridge, lines corresponding to bridges are copied from the input map to the output map. On the other hand, for method=articulation, points are created on the positions of articulation points.

In GRASS GIS, line is not always a single line segment. It might be, and often is, a sequence of line segments between two intersections. Also, articulation point is a standard graph theoretic terminology which is slightly misleading in GRASS. An articulation point in graph theory is an articulation node in GRASS terminology.