[Pellet-users] Problems with the Interface Pellet-Jena (performances and not only)

[Andrea Splendiani]

Hi,

I have a problem with the interface between Pellet and Jena.

That is:

OntModel myBasicKnowledge
myOntoKnowledge=ModelFactory.createOntologyModel 
(PelletReasonerFactory.THE_SPEC,myBasicKnowledge);
myOntoKnowledge.prepare();
...
OntModel newModel.add(myOntoKnowledge)
^^^
At this point, it starts a huge computation (For small ontologies, it  
is still reasonable, but it's undoable for bigger ones) (Note:  
small=~10^2 classes+instances bigger=10^4).

Now, pellet command line and programmatic classification and  
realization tasks are fast.

When I add the model to an ontology, I guess it issues a  
listStatements(), I think that at its time prompts the expansion of  
all possible relations and classes in the ontology, and here lie my  
problem. Or at least that's my guess.

Can this be avoided ?

classification would be enough of a computation for me (ideally, I  
would like to have computations on demand driven by the Jena model).

Digging on the wen, I've come to the following code:


Model tempModel=myOntoKnowledge.getBaseModel();
OntModel tempModel2=ModelFactory.createOntologyModel 
(PelletReasonerFactory.THE_SPEC,tempModel);
tempModel2.prepare();
OWLReasoner reasoner = ((PelletInfGraph)tempModel2.getGraph 
()).getOWLReasoner();
reasoner.classify();
reasoner.realize();
myOntoKnowledge=ModelFactory.createOntologyModel(OntModelSpec.OWL_MEM);
Model m=reasoner.extractModel(false);
^^^^^^
Here still huge computation.
				
Any hint/help ?

Andrea Splendiani

				


-----------
Andrea Splendiani
post-doc, bootstrep project (www.bootstrep.eu)

UPRES-EA 3888 - Laboratoire d'Informatique Médicale
CHU de Pontchaillou
2, rue Henri Le Guilloux
35033 Rennes - France
Tel : +33 2 99 28 92 45 / +33 2 99 28 42 15 (secr.)
Fax : +33 2 99 28 41 60

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1° 41.643W






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