Class DirectedScaleFreeGraphGenerator<V,E>
 java.lang.Object

 org.jgrapht.generate.DirectedScaleFreeGraphGenerator<V,E>

 Type Parameters:
V
 the graph vertex typeE
 the graph edge type
 All Implemented Interfaces:
GraphGenerator<V,E,V>
public class DirectedScaleFreeGraphGenerator<V,E> extends Object implements GraphGenerator<V,E,V>
A generator for directed scalefree graphs.This generator creates a directed scalefree graph according to a power law, as described in Bollobás et al. The paper can be cited as Béla Bollobás, Christian Borgs, Jennifer Chayes, and Oliver Riordan. "Directed scalefree graphs." Proceedings of the fourteenth annual ACMSIAM symposium on Discrete algorithms. Society for Industrial and Applied Mathematics, 2003.
In This generator, the graph continues to grow one edge per step, according to the probabilities alpha, beta, and gamma (which sum up to 1).
 alpha is the probability that the new edge is from a new vertex v to an existing vertex w, where w is chosen according to d_in + delta_in.
 beta is the probability that the new edge is from an existing vertex v to an existing vertex w, where v and w are chosen independently, v according to d_out + delta_out, and w according to d_in + delta_in.
 gamma is the probability that the new edge is from an existing vertex v to a new vertex w, where v is chosen according to d_out + delta_out.
In their original paper, the graph continues to grow according to a certain power law until a certain number of edges is reached irrespective to the number of nodes.
However, because the target number of edges is not known beforehand, in this implementation, we added another feature that enables the user to grow the curve according to that power law until the target number of edges or target number of nodes is reached. Author:
 Amr ALHOSSARY


Constructor Summary
Constructors Constructor Description DirectedScaleFreeGraphGenerator(float alpha, float gamma, float deltaIn, float deltaOut, int targetEdges, int targetNodes)
Constructs a Generator.DirectedScaleFreeGraphGenerator(float alpha, float gamma, float deltaIn, float deltaOut, int targetEdges, int targetNodes, long seed)
Constructs a Generator using a seed for the random number generator.DirectedScaleFreeGraphGenerator(float alpha, float gamma, float deltaIn, float deltaOut, int targetEdges, int targetNodes, long seed, boolean allowingMultipleEdges, boolean allowingSelfLoops)
Constructs a Generator using a seed for the random number generator and sets the two relaxation optionsallowingMultipleEdges
andallowingSelfLoops
.DirectedScaleFreeGraphGenerator(float alpha, float gamma, float deltaIn, float deltaOut, int targetEdges, int targetNodes, Random rng)
Construct a new generator using the provided random number generator.DirectedScaleFreeGraphGenerator(float alpha, float gamma, float deltaIn, float deltaOut, int targetEdges, int targetNodes, Random rng, boolean allowingMultipleEdges, boolean allowingSelfLoops)
Construct a new generator using the provided random number generator and sets the two relaxation optionsallowingMultipleEdges
andallowingSelfLoops
.

Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
generateGraph(Graph<V,E> target, Map<String,V> resultMap)
Generates an instance of theGraph
.int
getMaxFailures()
Returns the maximum allowed number of consecutive failed attempts to add an edge.boolean
isAllowingMultipleEdges()
Returns whether the generated graph may contain multiple (parallel) edges between the same two vertices.boolean
isAllowingSelfLoops()
Returns whether the generated graph may contain multiple (parallel) edges between the same two verticesvoid
setAllowingMultipleEdges(boolean allowingMultipleEdges)
Sets whether the generated graph may contain multiple (parallel) edges between the same two verticesvoid
setAllowingSelfLoops(boolean allowingSelfLoops)
Sets whether the generated graph may contain multiple (parallel) edges between the same two verticesvoid
setMaxFailures(int maxFailures)
Sets the maximum allowed number of consecutive failed attempts to add an edge (must be non negative).
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 Detail

DirectedScaleFreeGraphGenerator
public DirectedScaleFreeGraphGenerator(float alpha, float gamma, float deltaIn, float deltaOut, int targetEdges, int targetNodes)
Constructs a Generator. Parameters:
alpha
 The probability that the new edge is from a new vertex v to an existing vertex w, where w is chosen according to d_in + delta_in.gamma
 The probability that the new edge is from an existing vertex v to a new vertex w, where v is chosen according to d_out + delta_out.deltaIn
 The indegree bias used for Alpha and Beta.deltaOut
 The outdegree bias used for Beta and Gamma.targetEdges
 Target total number of edges to reach. It has a higher priority thantargetNodes
. Zero is a valid value.
If negative number, the user does not care about the total number of edges and is interested only in the number of nodes, therefore,targetNodes
will be considered instead. Otherwise,targetEdges
will be considered andtargetEdges
will be ignored.targetNodes
 Target number of nodes to reach. Zero is a valid value.
This parameter has lower priority thantargetEdges
and will be used only iftargetEdges
given is a negative number.

DirectedScaleFreeGraphGenerator
public DirectedScaleFreeGraphGenerator(float alpha, float gamma, float deltaIn, float deltaOut, int targetEdges, int targetNodes, long seed)
Constructs a Generator using a seed for the random number generator. Parameters:
alpha
 The probability that the new edge is from a new vertex v to an existing vertex w, where w is chosen according to d_in + delta_in.gamma
 The probability that the new edge is from an existing vertex v to a new vertex w, where v is chosen according to d_out + delta_out.deltaIn
 The indegree bias used for Alpha and Beta.deltaOut
 The outdegree bias used for Beta and Gamma.targetEdges
 Target total number of edges to reach. It has a higher priority thantargetNodes
. Zero is a valid value.
If negative number, the user does not care about the total number of edges and is interested only in the number of nodes, therefore,targetNodes
will be considered instead. Otherwise,targetEdges
will be considered andtargetEdges
will be ignored.targetNodes
 Target number of nodes to reach. Zero is a valid value.
This parameter has lower priority thantargetEdges
and will be used only iftargetEdges
given is a negative number.seed
 The seed to feed to the random number generator.

DirectedScaleFreeGraphGenerator
public DirectedScaleFreeGraphGenerator(float alpha, float gamma, float deltaIn, float deltaOut, int targetEdges, int targetNodes, long seed, boolean allowingMultipleEdges, boolean allowingSelfLoops)
Constructs a Generator using a seed for the random number generator and sets the two relaxation optionsallowingMultipleEdges
andallowingSelfLoops
. Parameters:
alpha
 The probability that the new edge is from a new vertex v to an existing vertex w, where w is chosen according to d_in + delta_in.gamma
 The probability that the new edge is from an existing vertex v to a new vertex w, where v is chosen according to d_out + delta_out.deltaIn
 The indegree bias used for Alpha and Beta.deltaOut
 The outdegree bias used for Beta and Gamma.targetEdges
 Target total number of edges to reach. It has a higher priority thantargetNodes
. Zero is a valid value.
If negative number, the user does not care about the total number of edges and is interested only in the number of nodes, therefore,targetNodes
will be considered instead. Otherwise,targetEdges
will be considered andtargetEdges
will be ignored.targetNodes
 Target number of nodes to reach. Zero is a valid value.
This parameter has lower priority thantargetEdges
and will be used only iftargetEdges
given is a negative number.seed
 The seed to feed to the random number generator.allowingMultipleEdges
 whether the generator allows multiple parallel edges between the same two vertices (v, w).allowingSelfLoops
 whether the generator allows self loops from the a vertex to itself.

DirectedScaleFreeGraphGenerator
public DirectedScaleFreeGraphGenerator(float alpha, float gamma, float deltaIn, float deltaOut, int targetEdges, int targetNodes, Random rng)
Construct a new generator using the provided random number generator. Parameters:
alpha
 The probability that the new edge is from a new vertex v to an existing vertex w, where w is chosen according to d_in + delta_in.gamma
 The probability that the new edge is from an existing vertex v to a new vertex w, where v is chosen according to d_out + delta_out.deltaIn
 The indegree bias used for Alpha and Beta.deltaOut
 The outdegree bias used for Beta and Gamma.targetEdges
 Target total number of edges to reach. It has a higher priority thantargetNodes
. Zero is a valid value.
If negative number, the user does not care about the total number of edges and is interested only in the number of nodes, therefore,targetNodes
will be considered instead. Otherwise,targetEdges
will be considered andtargetEdges
will be ignored.targetNodes
 Target number of nodes to reach. Zero is a valid value.
This parameter has lower priority thantargetEdges
and will be used only iftargetEdges
given is a negative number.rng
 TheRandom
object to use.

DirectedScaleFreeGraphGenerator
public DirectedScaleFreeGraphGenerator(float alpha, float gamma, float deltaIn, float deltaOut, int targetEdges, int targetNodes, Random rng, boolean allowingMultipleEdges, boolean allowingSelfLoops)
Construct a new generator using the provided random number generator and sets the two relaxation optionsallowingMultipleEdges
andallowingSelfLoops
. Parameters:
alpha
 The probability that the new edge is from a new vertex v to an existing vertex w, where w is chosen according to d_in + delta_in.gamma
 The probability that the new edge is from an existing vertex v to a new vertex w, where v is chosen according to d_out + delta_out.deltaIn
 The indegree bias used for Alpha and Beta.deltaOut
 The outdegree bias used for Beta and Gamma.targetEdges
 Target total number of edges to reach. It has a higher priority thantargetNodes
. Zero is a valid value.
If negative number, the user does not care about the total number of edges and is interested only in the number of nodes, therefore,targetNodes
will be considered instead. Otherwise,targetEdges
will be considered andtargetEdges
will be ignored.targetNodes
 Target number of nodes to reach. Zero is a valid value.
This parameter has lower priority thantargetEdges
and will be used only iftargetEdges
given is a negative number.rng
 TheRandom
object to use.allowingMultipleEdges
 whether the generator allows multiple parallel edges between the same two vertices (v, w).allowingSelfLoops
 whether the generator allows self loops from the a vertex to itself.


Method Detail

generateGraph
public void generateGraph(Graph<V,E> target, Map<String,V> resultMap)
Generates an instance of theGraph
. Specified by:
generateGraph
in interfaceGraphGenerator<V,E,V>
 Parameters:
target
 the target graphresultMap
 not used by this generator, can be null Throws:
TooManyFailuresException
 When the method failsmaxFailures
times to add a new edge to the growing graph.IllegalArgumentException
 When the graph does not support Multiple edges or self loop while the generator does.

getMaxFailures
public int getMaxFailures()
Returns the maximum allowed number of consecutive failed attempts to add an edge. Returns:
 maxFailure field.

setMaxFailures
public void setMaxFailures(int maxFailures)
Sets the maximum allowed number of consecutive failed attempts to add an edge (must be non negative). Parameters:
maxFailures
 Maximum allowed (non negative) number of consecutive failed attempts to add an edge.

isAllowingMultipleEdges
public boolean isAllowingMultipleEdges()
Returns whether the generated graph may contain multiple (parallel) edges between the same two vertices. Returns:
 whether the generated graph may contain multiple (parallel) edges between the same two vertices

setAllowingMultipleEdges
public void setAllowingMultipleEdges(boolean allowingMultipleEdges)
Sets whether the generated graph may contain multiple (parallel) edges between the same two vertices Parameters:
allowingMultipleEdges
 whether the generated graph may contain multiple (parallel) edges between the same two vertices

isAllowingSelfLoops
public boolean isAllowingSelfLoops()
Returns whether the generated graph may contain multiple (parallel) edges between the same two vertices Returns:
 whether the generated graph many contain multiple (parallel) edges between the same two vertices

setAllowingSelfLoops
public void setAllowingSelfLoops(boolean allowingSelfLoops)
Sets whether the generated graph may contain multiple (parallel) edges between the same two vertices Parameters:
allowingSelfLoops
 whether the generated graph many contain multiple (parallel) edges between the same two vertices

