igraph (version 0.1.2)

barabasi.game: Generate scale-free graphs according to the Barabasi-Albert model

Description

The BA-model is a very simple stochastic algorithm for building a graph.

Usage

barabasi.game(n, m = NULL, out.dist = NULL, out.seq = NULL, out.pref = FALSE, 
              directed=TRUE)

Arguments

n

Number of vertices.

m

Numeric constant, the contant out-degree of the vertices.

out.dist

Numeric vector, the distiribution of the out-degree.

out.seq

Numeric vector, the out-degree sequence of the vertices

out.pref

Logical, if true the total degree is used for calculating the citation probability, otherwise the in-degree is used.

directed

Whether to create a directed graph.

Value

• A graph object.

Details

The out-degree of the vertices is determined by the m, out.dist and out.seq parameters, only at most one of these should be not NULL. If all of these are NULL, then constant out-degree one is used. If m is not NULL, it specifies the constant out-degree.

Otherwise if out.dist is not NULL, it is used to generate an out-degree sequence, the maximum out-degree is length(out.dist)-1 and the probability of having out-degree $k$ is out.dist[k+1]/sum(out.dist).

Otherwise if out.seq is not NULL it is used directly as the out-degrees of the vertices. Its length should be exactly n.

References

Barab�si, A.-L. and Albert R. 1999. Emergence of scaling in random networks Science, 286 509--512.

See Also

random.graph.game

Examples

g <- barabasi.game(1000)
degree.distribution(g)