org.jgrapht.generate
Class RandomGraphGenerator.DefaultEdgeTopologyFactory<VV,EE>

java.lang.Object
  extended by 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
    RandomGraphGenerator.DefaultEdgeTopologyFactory()
               
     
    Method Summary
     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:
     
    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.