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v.net.spanningtree

Computes minimum spanning tree for the network.

v.net.spanningtree [-g] input=name output=name [arc_layer=string] [node_layer=string] [arc_column=name] [node_column=name] [--overwrite] [--verbose] [--quiet] [--qq] [--ui]

Example:

v.net.spanningtree input=name output=name

grass.script.run_command("v.net.spanningtree", input, output, arc_layer="1", node_layer="2", arc_column=None, node_column=None, flags=None, overwrite=False, verbose=False, quiet=False, superquiet=False)

Example:

gs.run_command("v.net.spanningtree", input="name", output="name")

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)
node_column=name
    Node cost column (number)
-g
    Use geodesic calculation for longitude-latitude projects
--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
output : str, required
    Name for output vector map
    Used as: output, 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
arc_column : str, optional
    Arc forward/both direction(s) cost column (number)
    Used as: input, dbcolumn, name
node_column : str, optional
    Node cost column (number)
    Used as: input, dbcolumn, name
flags : str, optional
    Allowed values: g
    g
        Use geodesic calculation for longitude-latitude projects
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.spanningtree finds the minimum spanning tree in a network.

NOTES

A spanning tree is a minimum cost subnetwork connecting all nodes in an undirected network (same forward and backward costs). If a network is disconnected then the module computes the minimum spanning tree for each (weakly) connected component. So, strictly speaking, v.net.spanningtree does not compute spanning tree but a spanning forest. As the name suggests, a spanning tree is a tree. That is, it contains no cycles and if a component has N nodes then the tree has N-1 edges connecting all nodes. Accol is used to specify the costs of the edges. The output consists of the edges in the spanning tree.

EXAMPLES

Find cheapest set of pipelines connecting all nodes.

v.net.spanningtree input=projected_pipelines output=spanningtree accol=cost

SEE ALSO

v.net, v.net.steiner

AUTHORS

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

SOURCE CODE

Available at: v.net.spanningtree source code (history)
Latest change: Friday Feb 07 19:16:09 2025 in commit a82a39f