graph
Class Graph

java.lang.Object
  graph.Graph

public class Graph

extends java.lang.Object

An un-directed graph

Nested Class Summary

(package private) class

Graph.Node An instance of this class represents one node of the graph

Field Summary

(package private) static boolean	debug
(package private) Graph.Node[]	node The nodes of the graph.

Constructor Summary

Graph(int N, double D)
Constructs a random graph with N nodes and (N*D)/2 edges

Method Summary

(package private) void	displayEquiv(NodeInfo[] w) Show how the nodes are divided into classes of equivalency
int	getNodeDegree(int i)
int	getNodeNeigh(int i, int j)
int	getNodeNum()
static void	main(java.lang.String[] arg) Converts a Graph to a ConceptSystem.
boolean	mayBeSymmetric() Tests whether this graph may have some symmetry, by means of looking at N topological invariants of the vertices.
boolean	mayBeSymmetric(int maxNI) Tests whether this graph may have some symmetry, by means of looking at topological invariants of the vertices.
Graph	permute(int[] p) Permutes the graph.
static int[]	randomPermutation(int n) Returns an array of integers, from 0 to n-1, randomly permuted.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

debug

static boolean debug

node

Graph.Node[] node

The nodes of the graph. Use the size of this array to find the number of nodes in the graph

Constructor Detail

Graph

public Graph(int N,
             double D)
      throws java.lang.Exception

Constructs a random graph with N nodes and (N*D)/2 edges

Method Detail

getNodeNum

public int getNodeNum()

getNodeDegree

public int getNodeDegree(int i)

getNodeNeigh

public int getNodeNeigh(int i,
                        int j)

toString

public java.lang.String toString()

displayEquiv

void displayEquiv(NodeInfo[] w)

Show how the nodes are divided into classes of equivalency

mayBeSymmetric

public boolean mayBeSymmetric()

Tests whether this graph may have some symmetry, by means of looking at N topological invariants of the vertices.

Returns:

false is we have proven that the graph is asymmetric, by studying the topological invariants of its nodes; true if we have failed to prove asymmetry, which means that the graph may (or may not) be symmetric.

mayBeSymmetric

public boolean mayBeSymmetric(int maxNI)

Tests whether this graph may have some symmetry, by means of looking at topological invariants of the vertices.

Parameters:

maxNI - How many invariants to test. If -1 is passed, the method will test N invariants. In practice, 5 or 10 probably would be enough for most random graphs.

Returns:

false is we have proven that the graph is asymmetric, by studying the topological invariants of its nodes; true if we have failed to prove asymmetry, which means that the graph may (or may not) be symmetric.

randomPermutation

public static int[] randomPermutation(int n)

Returns an array of integers, from 0 to n-1, randomly permuted.

permute

public Graph permute(int[] p)

Permutes the graph. In the new graph, the p[0]-th node is the image of the 0-th node in the graph, etc.

Parameters:

p - Permute according to this table.

main

public static void main(java.lang.String[] arg)
                 throws java.lang.Exception

Converts a Graph to a ConceptSystem.

Throws:

java.lang.Exception