Connectivity#

Algorithm ID: hedgetools:connectivity

This tool compute connectivity metrics describing the hedge sub-network. The tool first reconstructs the sub-networks. A sub-network is a cluster of connected arcs, so multiple arcs can belong to the same sub-network if they are connected.

Parameters#

Label	Name	Type	Description
Input arc layer	`INPUT_ARC`	[vector: line]	Line vector layer representing the hedge median axis.
Input node layer	`INPUT_NODE`	[vector: point]	Point vector layer of hedge extremities.
Input polygon layer	`INPUT_POLYGON`	[vector: polygon] Optional	Polygon vector layer representing the hedges.
Spatial threshold (meters)	`THRESHOLD`	[numeric: double]	Distance threshold used to consider hedges without a physical connection as connected.
Override network construction from attributes	`OVERRIDE`	[boolean] Default: True	If toggled, will not use the `network_id` and `n_threshold` fields to build the network but the specified `Spatial threshold` value.
Output connectivity layer	`OUTPUT`	[vector: line] Default: `[Create temporary layer]`	Output line vector layer.

Outputs#

Label	Name	Type	Description
Output connectivity layer	`OUTPUT`	[vector: line]	Line vector layer with two new fields describing the nerworks : `network_id`: Unique identifier of the network. Hedges sharing the same ID belong to the same network. `n_threshold`: Distance threshold used to consider hedges without a physical connection as connected. And tne new fields of network metrics: `edges_count`: Number of links – number of edges within the network. `nodes_count`: Number of nodes – number of vertices within the network. `cyclomatic_number`: Cyclomatic number – number of cycles within the network. `network_length`: Network length – total length of the network in meters. `alpha_index`: Alpha index – proportion of existing cycles to the total possible number. Value ranges from 0 to 1. `beta_index`: Beta index – average number of edges per vertex. Value ranges from 0 to 1. `gamma_index`: Gamma index – proportion of network edges to the total possible number. Value ranges from 0 to 1. `eta_index`: Eta index – average length of an edge. `detour_index`: Detour index – proportion between the sum of Euclidean distances for each point pair and the actual network distance. Value ranges from 0 to 1. `network_density`: Network density – network length divided by the area of its bounding box.

Label

Name

Type

Description

Output connectivity layer

OUTPUT

[vector: line]

Line vector layer with two new fields describing the nerworks :

network_id: Unique identifier of the network. Hedges sharing the same ID belong to the same network.
n_threshold: Distance threshold used to consider hedges without a physical connection as connected.

And tne new fields of network metrics:

edges_count: Number of links – number of edges within the network.
nodes_count: Number of nodes – number of vertices within the network.
cyclomatic_number: Cyclomatic number – number of cycles within the network.
network_length: Network length – total length of the network in meters.
alpha_index: Alpha index – proportion of existing cycles to the total possible number. Value ranges from 0 to 1.
beta_index: Beta index – average number of edges per vertex. Value ranges from 0 to 1.
gamma_index: Gamma index – proportion of network edges to the total possible number. Value ranges from 0 to 1.
eta_index: Eta index – average length of an edge.
detour_index: Detour index – proportion between the sum of Euclidean distances for each point pair and the actual network distance. Value ranges from 0 to 1.
network_density: Network density – network length divided by the area of its bounding box.