kCores: Find all the k-cores in a graph
In RBGL: An interface to the BOOST graph library

Description Usage Arguments Details Value Author(s) References Examples

Find all the k-cores in a graph

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

`g`	an instance of the `graph` class
`EdgeType`	what types of edges to be considered when `g` is directed

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.

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

Li Long <li.long@isb-sib.ch>

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.

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")