com.hp.hpl.mesa.rdf.jena.common
Class ModelMatcher

java.lang.Object
  |
  +--com.hp.hpl.mesa.rdf.jena.common.ModelMatcher

public class ModelMatcher

extends java.lang.Object

An implemantation of graph isomorphism for Model equality. The underlying algorithm is exponential but will only enter a non-deterministic polynomial part when there are a lot of difficult to distinguish anonymous nodes connected to each other by statements with the same property(s). Non-pathological examples, where most nodes have some properties that help distinguish them from other nodes, will experience nearly linear performance.

The documentation at Model.equals was not written by a mathematician and is hence more readable.

Version:

Release='$Name: $' Revision='$Revision: 1.3 $' Date='$Date: 2001/09/21 08:38:27 $'

Author:

jjc

See Also:

Model.equals(java.lang.Object)

Method Summary

static boolean	equals(Model m1, Model m2) Are the two models isomorphic.
static Resource[][]	match(Model m1, Model m2) Return an isomorphism between the two models.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

equals

public static boolean equals(Model m1,
                             Model m2)
                      throws RDFException

Are the two models isomorphic. The isomorphism is defined as a bijection between the anonymous variables such that the statements are identical.

See Also:

For a less mathematical explanation.

match

public static Resource[][] match(Model m1,
                                 Model m2)
                          throws RDFException

Return an isomorphism between the two models. This function is nondeterministic in that it may return a different bijection on each call, in cases where there are multiple isomorphisms between the models.

Returns:

null on failure or an array of related pairs (arrays of length 2) of anonymous resources. match(m1,m2)[i][0] is from m1, and match(m1,m2)[i][1] is the corresponding node in m2.