netrankr (version 2.0.0)

swan_efficiency: Impact on farness when a node is removed

Description

swan_efficiency measures the change in the sum of distances between all node pairs when excluding a node from the network.

Usage

swan_efficiency(g)

Value

A numeric vector where each entry represents the swan_efficiency value for the corresponding node.

Arguments

g

An igraph object representing the graph to analyze.

Details

swan_efficiency is based on geographic accessibility, similar to indices used for assessing transportation network performance, such as closeness accessibility. It quantifies the impact of node removal by calculating the change in the sum of distances between all node pairs.

As in NetSwan, the sum of distances is infinite if the graph is disconnected. The value of a node is therefore Inf if its removal disconnects the graph and NaN for all nodes if the graph is already disconnected.

The code is an adaptation from the NetSwan package that was archived on CRAN.

References

Lhomme S. (2015). Analyse spatiale de la structure des réseaux techniques dans un contexte de risques. Cybergeo: European Journal of Geography.

Examples

library(igraph)
# Example graph (electrical network structure)
elec <- matrix(ncol = 2, byrow = TRUE, c(
  11,1, 11,10, 1,2, 2,3, 2,9,
  3,4, 3,8, 4,5, 5,6, 5,7,
  6,7, 7,8, 8,9, 9,10
))
gra <- graph_from_edgelist(elec, directed = FALSE)

# Compute efficiency impact of node removal
f2 <- swan_efficiency(gra)
bet <- betweenness(gra)
reg <- lm(bet ~ f2)
summary(reg)