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

AUTHORS

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

SOURCE CODE

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