Class BarabasiAlbertForestGenerator<V,E>
- java.lang.Object
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- org.jgrapht.generate.BarabasiAlbertForestGenerator<V,E>
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- Type Parameters:
V
- the graph vertex typeE
- 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
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Constructor Summary
Constructors Constructor Description BarabasiAlbertForestGenerator(int t, int n)
ConstructorBarabasiAlbertForestGenerator(int t, int n, long seed)
ConstructorBarabasiAlbertForestGenerator(int t, int n, java.util.Random rng)
Constructor
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Method Summary
All Methods Instance Methods Concrete Methods 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
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Methods inherited from interface org.jgrapht.generate.GraphGenerator
generateGraph
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Constructor Detail
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BarabasiAlbertForestGenerator
public BarabasiAlbertForestGenerator(int t, int n)
Constructor- Parameters:
t
- number of treesn
- final number of nodes- Throws:
java.lang.IllegalArgumentException
- in case of invalid parameters
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BarabasiAlbertForestGenerator
public BarabasiAlbertForestGenerator(int t, int n, long seed)
Constructor- Parameters:
t
- number of treesn
- final number of nodesseed
- seed for the random number generator- Throws:
java.lang.IllegalArgumentException
- in case of invalid parameters
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BarabasiAlbertForestGenerator
public BarabasiAlbertForestGenerator(int t, int n, java.util.Random rng)
Constructor- Parameters:
t
- number of treesn
- final number of nodesrng
- the random number generator to use- Throws:
java.lang.IllegalArgumentException
- in case of invalid parameters
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Method Detail
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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 interfaceGraphGenerator<V,E,V>
- Parameters:
target
- the target graphresultMap
- not used by this generator, can be null- Throws:
java.lang.NullPointerException
- iftarget
isnull
java.lang.IllegalArgumentException
- iftarget
is not undirectedjava.lang.IllegalArgumentException
- iftarget
is not empty
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