GRASS GIS manual: v.net.connectivity

## NAME

v.net.connectivity - Computes vertex connectivity between two sets of nodes in the network.

## KEYWORDS

vector, network, connectivity

## SYNOPSIS

v.net.connectivity
v.net.connectivity --help
v.net.connectivity input=name [arc_layer=string] [node_layer=string] [arc_column=name] [arc_backward_column=name] output=name [node_column=name] [set1_cats=range] [set1_where=sql_query] [set2_cats=range] [set2_where=sql_query] [--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
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)
output=name [required]
  Name for output vector map
node_column=name
  Node cost column (number)
set1_cats=range
  Set1 category values
  Example: 1,3,7-9,13
set1_where=sql_query
  Set1 WHERE conditions of SQL statement without 'where' keyword
  Example: income < 1000 and population >= 10000
set2_cats=range
  Category values
  Set2 category values
set2_where=sql_query
  Set2 WHERE conditions of SQL statement without 'where' keyword
  Example: income < 1000 and population >= 10000

## DESCRIPTION

v.net.connectivity computes vertex connectivity between two sets, i.e. the minimum number of vertices whose removal would separate two given sets.

## NOTES

Two sets (set1 and set2) are specified by respective layer, where and cats parameters. Similarly to v.net.flow module, capacities of nodes can be given by node_column option. v.net.connectivity finds the set of nodes of minimum total capacitiy separating the two given sets and outputs map containing points on the positions of these nodes. Default capacity, which is used when no column is specified, is one.

## EXAMPLES

The following command finds the minimum number of intersections separating roads on the left bank from roads on the right bank.

    v.net.connectivity input=roads output=roads_conn set1_where="bank=left" \
          set2_where="bank=right"

    v.net.connectivity input=airtraffic output=connectivity \
          set1_where="name=JFK" set2_where="name=Heathrow" node_column=capacity

## SEE ALSO

v.net, v.net.flow, v.net.bridge

## AUTHORS

Daniel Bundala, Google Summer of Code 2009, Student
Wolf Bergenheim, Mentor

Last changed: $Date: 2014-12-24 14:28:25 +0100 (Wed, 24 Dec 2014) $

## SOURCE CODE

Available at: v.net.connectivity source code (history)

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© 2003-2018 GRASS Development Team, GRASS GIS 7.4.2 Reference Manual