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Select the k-Core of a Network

Source: R/wrangle-structure.R
select_k_core.Rd

The k-core is the maximal subgraph in which every node has degree at least k, found by repeatedly removing nodes of degree below k.

Usage

select_k_core(x, k, keep_format = FALSE, directed = NULL)

Arguments

x

Network input.

k

Integer. The core number.

keep_format

Logical. Return the input format when TRUE.

directed

Logical or NULL. If NULL (default), auto-detect.

Value

A cograph_network holding the k-core, or the input format when keep_format = TRUE. An empty network when no node reaches coreness k.

References

Seidman, S. B. (1983). Network structure and minimum degree. Social Networks, 5(3), 269–287.

See also

select_nodes, centrality

Examples

adj <- matrix(c(0, 1, 1, 1,
                1, 0, 1, 0,
                1, 1, 0, 0,
                1, 0, 0, 0), 4, 4, byrow = TRUE)
rownames(adj) <- colnames(adj) <- c("A", "B", "C", "D")

select_k_core(adj, k = 2)
#> Cograph network: 3 nodes, 3 edges ( undirected )
#> Source: matrix 
#>   Nodes (3): A, B, C
#>   Edges: 3 / 3 (density: 100.0%)
#>   Weights: [1.000, 1.000]  |  mean: 1.000
#>   Strongest edges:
#>     A -- B  1.000
#>     A -- C  1.000
#>     B -- C  1.000
#> Layout: none 
#>   Use as.data.frame() for the edge table, as.data.frame(what = "nodes") for the nodes.