RandomGraphGenerator.DefaultEdgeTopologyFactory (JGraphT : a free Java graph library)

java.lang.Object
- org.jgrapht.generate.RandomGraphGenerator.DefaultEdgeTopologyFactory<VV,EE>

All Implemented Interfaces:

RandomGraphGenerator.EdgeTopologyFactory<VV,EE>

Enclosing class:

RandomGraphGenerator<V,E>
```
public class RandomGraphGenerator.DefaultEdgeTopologyFactory<VV,EE>
extends java.lang.Object
implements RandomGraphGenerator.EdgeTopologyFactory<VV,EE>
```
Default implementation of the EdgeTopologyFactory interface. randomly chooses an edge and tries to add it. If the add fails from any reason (like: self edge / multiple edges in unpermitted graph type) it will just choose another and try again. Performance:
when the number of possible edges becomes slim , this class will have a very poor performance , cause it will not use gready methods to choose them. for example : In simple graph , if #V = N (#x = number Of x) and we want full mesh #edges= N*(N-1)/2 , the first added edges will do so quickly (O(1) , the last will take O(N^2). So , do not use it in this kind of graphs.
If the numberOfEdges is bigger than what the graph can add, there will be an infinite loop here. It is not tested.

Since:: Aug 6, 2005
Author:: Assaf

Constructor Summary

Constructors
Constructor and Description

RandomGraphGenerator.DefaultEdgeTopologyFactory()

Constructors
Constructor and Description
`RandomGraphGenerator.DefaultEdgeTopologyFactory()`

Method Summary

Modifier and Type Method and Description

void

createEdges(Graph<VV,EE> targetGraph,
           java.util.Map<java.lang.Integer,VV> orderToVertexMap,
           int numberOfEdges,
           java.util.Random randomizer)

Two different calls to the createEdges() with the same parameters must result in the generation of the same.

int

getMaxEdgesForVertexNum(Graph<VV,EE> targetGraph)

Return max edges for that graph.

boolean

isNumberOfEdgesValid(Graph<VV,EE> targetGraph,
                    int numberOfEdges)

checks if the numOfEdges is smaller than the Max edges according to the following table: Graph Type Directed / UnDirectedmultiple edgesloopsMax Edges SimpleGraph UnDirected - - N(N-1)/2 Multigraph UnDirected + - Infinite Pseudograph UnDirected + + Infinite SimpleDirectedGraph Directed - - N (N-1) DefaultDirectedGraph Directed - + N*(N-1)+ N = N^2 DirectedMultigraph Directed + + Infinite

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail
- RandomGraphGenerator.DefaultEdgeTopologyFactory
```
public RandomGraphGenerator.DefaultEdgeTopologyFactory()
```

Method Detail

createEdges
```
public void createEdges(Graph<VV,EE> targetGraph,
               java.util.Map<java.lang.Integer,VV> orderToVertexMap,
               int numberOfEdges,
               java.util.Random randomizer)
```
Description copied from interface: RandomGraphGenerator.EdgeTopologyFactory

Two different calls to the createEdges() with the same parameters must result in the generation of the same. But if the randomizer is different, it should, usually, create different edge topology.

Specified by:

createEdges in interface RandomGraphGenerator.EdgeTopologyFactory<VV,EE>

Parameters:
targetGraph - - guranteed to start with zero edges.
orderToVertexMap - - key=Integer of vertex order . between zero to numOfVertexes (exclusive). value = vertex from the graph. unique.
numberOfEdges - - to create in the graph

isNumberOfEdgesValid

public boolean isNumberOfEdgesValid(Graph<VV,EE> targetGraph,
                           int numberOfEdges)

checks if the numOfEdges is smaller than the Max edges according to the following table:

Graph Type	Directed / UnDirected	multiple edges	loops	Max Edges
SimpleGraph	UnDirected	-	-	N(N-1)/2
Multigraph	UnDirected	+	-	Infinite
Pseudograph	UnDirected	+	+	Infinite
SimpleDirectedGraph	Directed	-	-	N (N-1)
DefaultDirectedGraph	Directed	-	+	N*(N-1)+ N = N^2
DirectedMultigraph	Directed	+	+	Infinite

Specified by:: isNumberOfEdgesValid in interface RandomGraphGenerator.EdgeTopologyFactory<VV,EE>
Parameters:: targetGraph - guranteed to start with zero edges.
See Also:: RandomGraphGenerator.EdgeTopologyFactory.isNumberOfEdgesValid(Graph, int)

getMaxEdgesForVertexNum
```
public int getMaxEdgesForVertexNum(Graph<VV,EE> targetGraph)
```
Return max edges for that graph. If it is infinite return -1 instead.

All Classes

Summary:
Nested |
Field |
Constr |
Method

Detail:
Field |
Constr |
Method

Class RandomGraphGenerator.DefaultEdgeTopologyFactory<VV,EE>

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

RandomGraphGenerator.DefaultEdgeTopologyFactory

Method Detail

createEdges

isNumberOfEdgesValid

getMaxEdgesForVertexNum