Module org.jgrapht.core
Package org.jgrapht.generate

Class BarabasiAlbertForestGenerator<V,​E>

java.lang.Object
org.jgrapht.generate.BarabasiAlbertForestGenerator<V,​E>
Type Parameters:
V - the graph vertex type
E - the graph edge type
All Implemented Interfaces:
GraphGenerator<V,​E,​V>
public class BarabasiAlbertForestGenerator<V,​E>
extends java.lang.Object
implements GraphGenerator<V,​E,​V>
Barabási-Albert growth and preferential attachment forest generator.

The general graph generator is described in the paper: A.-L. Barabási and R. Albert. Emergence of scaling in random networks. Science, 286:509-512, 1999.

The generator starts with a $t$ isolated nodes and grows the network by adding $n - t$ additional nodes. The additional nodes are added one by one and each of them is connected to one previously added node, where the probability of connecting to a node is proportional to its degree.

Note that this Barabàsi-Albert generator only works on undirected graphs. For a version that works on both directed and undirected graphs and generates only connected graphs see BarabasiAlbertGraphGenerator.

Author:
Alexandru Valeanu

  • Constructor Summary

    Constructors 
    Constructor Description
    BarabasiAlbertForestGenerator​(int t, int n)
    Constructor
    BarabasiAlbertForestGenerator​(int t, int n, long seed)
    Constructor
    BarabasiAlbertForestGenerator​(int t, int n, java.util.Random rng)
    Constructor

  • Method Summary

    Modifier and Type Method Description
    void generateGraph​(Graph<V,​E> target, java.util.Map<java.lang.String,​V> resultMap)
    Generates an instance.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    Methods inherited from interface org.jgrapht.generate.GraphGenerator

    generateGraph

  • Constructor Details

    • BarabasiAlbertForestGenerator

      public BarabasiAlbertForestGenerator​(int t, int n)
      Constructor
      Parameters:
      t - number of trees
      n - final number of nodes
      Throws:
      java.lang.IllegalArgumentException - in case of invalid parameters

    • BarabasiAlbertForestGenerator

      public BarabasiAlbertForestGenerator​(int t, int n, long seed)
      Constructor
      Parameters:
      t - number of trees
      n - final number of nodes
      seed - seed for the random number generator
      Throws:
      java.lang.IllegalArgumentException - in case of invalid parameters

    • BarabasiAlbertForestGenerator

      public BarabasiAlbertForestGenerator​(int t, int n, java.util.Random rng)
      Constructor
      Parameters:
      t - number of trees
      n - final number of nodes
      rng - the random number generator to use
      Throws:
      java.lang.IllegalArgumentException - in case of invalid parameters

  • Method Details

    • generateGraph

      public void generateGraph​(Graph<V,​E> target, java.util.Map<java.lang.String,​V> resultMap)
      Generates an instance.

      Note: An exception will be thrown if the target graph is not empty (i.e. contains at least one vertex)

      Specified by:
      generateGraph in interface GraphGenerator<V,​E,​V>
      Parameters:
      target - the target graph
      resultMap - not used by this generator, can be null
      Throws:
      java.lang.NullPointerException - if target is null
      java.lang.IllegalArgumentException - if target is not undirected
      java.lang.IllegalArgumentException - if target is not empty