RBGL (version 1.48.1)

kCores: Find all the k-cores in a graph

Description

Find all the k-cores in a graph

Usage

kCores(g, EdgeType=c("in", "out"))

Arguments

g

an instance of the graph class

EdgeType

what types of edges to be considered when g is directed

Value

A vector of the core numbers for all the nodes in g.

Details

A k-core in a graph is a subgraph where each node is adjacent to at least a minimum number, k, of the other nodes in the subgraph.

A k-core in a graph may not be connected.

The core number for each node is the highest k-core this node is in. A node in a k-core will be, by definition, in a (k-1)-core.

The implementation is based on the algorithm by V. Batagelj and M. Zaversnik, 2002.

The example snacoreex.gxl is in the paper by V. Batagelj and M. Zaversnik, 2002.

References

Social Network Analysis: Methods and Applications. By S. Wasserman and K. Faust, pp. 266. An O(m) Algorithm for Cores decomposition of networks, by V. Batagelj and M. Zaversnik, 2002.

Examples

con1 <- file(system.file("XML/snacoreex.gxl",package="RBGL"))
kcoex <- fromGXL(con1)
close(con1)

kCores(kcoex)

con2 <- file(system.file("XML/conn2.gxl",package="RBGL"))
kcoex2 <- fromGXL(con2)
close(con2)

kCores(kcoex2)
kCores(kcoex2, "in")
kCores(kcoex2, "out")