Betweenness of each node — ntbtw • crimlab

The sum, over pairs of other nodes, of the share of their shortest paths that pass through the node (Freeman 1977), by Brandes' algorithm in O(nodes x edges) time. Paths are counted in steps: weights are tie strengths, not lengths, and are not taken. An undirected pair is counted once. Graph rules as in ntdeg().

Usage

ntbtw(from, to, nodes = NULL, dir = FALSE, norm = FALSE)

Arguments

from, to: Labels of the two ends of each edge: vectors of the same length (zero when nodes gives every node) with no missing values.
nodes: NULL, or every node's label once: the node order of the results and the way to include isolated nodes.
dir: TRUE for a directed graph (from sends a tie to to).
norm: TRUE to divide by the number of pairs of other nodes, (n - 1)(n - 2) directed or (n - 1)(n - 2) / 2 undirected, as igraph::betweenness(normalized = TRUE) does; NaN for fewer than 3 nodes.

Value

A data frame: node, btw.

References

Brandes, U. (2001). A faster algorithm for betweenness centrality. Journal of Mathematical Sociology, 25(2), 163-177. doi:10.1080/0022250X.2001.9990249

Freeman, L. C. (1977). A set of measures of centrality based on betweenness. Sociometry, 40(1), 35-41. doi:10.2307/3033543

Examples

ntbtw(c(1, 2, 3), c(2, 3, 4))
#>   node btw
#> 1    1   0
#> 2    2   2
#> 3    3   2
#> 4    4   0