kCores {RBGL} | R Documentation

## 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

### 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.

### Value

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

### Author(s)

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

### 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")

[Package RBGL version 1.56.0 Index]