v.net.centrality
Computes degree, centrality, betweeness, closeness and eigenvector centrality measures in the network.
v.net.centrality [-ga] input=name [arc_layer=string] [node_layer=string] output=name [cats=range] [where=sql_query] [arc_column=name] [arc_backward_column=name] [node_column=string] [degree=name] [closeness=name] [betweenness=name] [eigenvector=name] [iterations=integer] [error=float] [--overwrite] [--verbose] [--quiet] [--qq] [--ui]
Example:
v.net.centrality input=name output=name
grass.script.run_command("v.net.centrality", input, arc_layer="1", node_layer="2", output, cats=None, where=None, arc_column=None, arc_backward_column=None, node_column=None, degree=None, closeness=None, betweenness=None, eigenvector=None, iterations=1000, error=0.1, flags=None, overwrite=False, verbose=False, quiet=False, superquiet=False)
Example:
gs.run_command("v.net.centrality", input="name", output="name")
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
output=name [required]
Name for output vector map
cats=range
Category values
Example: 1,3,7-9,13
where=sql_query
WHERE conditions of SQL statement without 'where' keyword
Example: income < 1000 and population >= 10000
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)
degree=name
Name of degree centrality column
closeness=name
Name of closeness centrality column
betweenness=name
Name of betweenness centrality column
eigenvector=name
Name of eigenvector centrality column
iterations=integer
Maximum number of iterations to compute eigenvector centrality
Default: 1000
error=float
Cumulative error tolerance for eigenvector centrality
Default: 0.1
-g
Use geodesic calculation for longitude-latitude projects
-a
Add points on nodes
--overwrite
Allow output files to overwrite existing files
--help
Print usage summary
--verbose
Verbose module output
--quiet
Quiet module output
--qq
Very quiet module output
--ui
Force launching GUI dialog
input : str, required
Name of input vector map
Or data source for direct OGR access
Used as: input, vector, name
arc_layer : str, optional
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.
Used as: input, layer
Default: 1
node_layer : str, optional
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.
Used as: input, layer
Default: 2
output : str, required
Name for output vector map
Used as: output, vector, name
cats : str, optional
Category values
Example: 1,3,7-9,13
Used as: input, cats, range
where : str, optional
WHERE conditions of SQL statement without 'where' keyword
Example: income < 1000 and population >= 10000
Used as: input, sql_query, sql_query
arc_column : str, optional
Arc forward/both direction(s) cost column (number)
Used as: input, dbcolumn, name
arc_backward_column : str, optional
Arc backward direction cost column (number)
Used as: input, dbcolumn, name
node_column : str, optional
Node cost column (number)
degree : str, optional
Name of degree centrality column
Used as: input, dbcolumn, name
closeness : str, optional
Name of closeness centrality column
Used as: input, dbcolumn, name
betweenness : str, optional
Name of betweenness centrality column
Used as: input, dbcolumn, name
eigenvector : str, optional
Name of eigenvector centrality column
Used as: input, dbcolumn, name
iterations : int, optional
Maximum number of iterations to compute eigenvector centrality
Default: 1000
error : float, optional
Cumulative error tolerance for eigenvector centrality
Default: 0.1
flags : str, optional
Allowed values: g, a
g
Use geodesic calculation for longitude-latitude projects
a
Add points on nodes
overwrite: bool, optional
Allow output files to overwrite existing files
Default: False
verbose: bool, optional
Verbose module output
Default: False
quiet: bool, optional
Quiet module output
Default: False
superquiet: bool, optional
Very quiet module output
Default: False
DESCRIPTION
v.net.centrality computes degree, closeness, betweenness and eigenvector centrality measures.
NOTES
The module computes various centrality measures for each node and stores
them in the given columns of an attribute table, which is created and
linked to the output map. For the description of these, please check the
following wikipedia article.
If the column name is not given for a measure then that measure is not
computed. If -a flag is set then points are added on nodes without
points. Also, the points for which the output is computed can be
specified by cats, layer and where parameters. However, if
any of these parameters is present then -a flag is ignored and no
new points are added.
Betweenness measure is not normalised. In order to get the normalised
values (between 0 and 1), each number needs to be divided by N choose
2=N*(N-1)/2 where N is the number of nodes in the connected component.
Computation of eigenvector measure terminates if the given number of
iterations is reached or the cumulative squared error between the
successive iterations is less than error.
EXAMPLES
Compute closeness and betweenness centrality measures for each node and produce a map containing not only points already present in the input map but a map with point on every node.
v.net.centrality input=roads output=roads_cent closeness=closeness \
betweenness=betweenness -a
SEE ALSO
AUTHORS
Daniel Bundala, Google Summer of Code 2009, Student
Wolf Bergenheim, Mentor
SOURCE CODE
Available at: v.net.centrality source code
(history)
Latest change: Friday Feb 07 19:16:09 2025 in commit a82a39f