[Pellet-users] OWL API Reasoner and OWLOntologyManager

[Evren Sirin]

On 2/26/08 1:39 AM, Swanson, Tim wrote:
>
> I'm not sure whether this is a Pellet question or an OWL API question. 
> I think it's a Pellet question, so I'm going to ask here first.
>

I think this is a question for both Pellet and OWL API and I can answer 
it from Pellet's point-of-view.
>
>
> The Pellet implementation of the OWL API reasoner classes 
> (org.mindswap.pellet.owlapi.Reasoner) takes an OWLOntologyManager as a 
> constructor argument and has a getManager() method. (As far as I can 
> tell, the method isn't required by any of the OWL API interfaces.)
>

Not explicitly but the design of OWLAPI requires you to have the manager 
for couple of reasons. One reason is to get the imports of an ontology. 
The ontology object itself only gives you the imported URIs not ontology 
objects and if you'd like the reasoner to load imports automatically you 
need to provide the manager for that ontology. The other reason is 
conversion from Pellet representation (ATerms) to OWLAPI objects 
requires a OWLDataFactory that is given by a manager. You will see that 
many (maybe all?) other reasoner implementations require a manager in 
the constructor.

>
> Why does the reasoner have the OWLOntologyManager object? 
> Specifically, what happens if I try to load an ontology into the 
> reasoner that is not managed by that manager? (i.e. 
> reasoner.getManager.getOntologies().contains(ontology) returns false.)
>

The only implication would be that imported ontologies would not be 
loaded automatically. If the ontologies you are loading do not have 
imports or you disabled imports processing by 
Reasoner.getLoader().setProcessImports(false) then this would not have 
any effect at all. The data factories inside managers handle caching the 
objects for named terms which might have an impact in memory if you 
create too many manager instances but that would not affect the behavior 
of reasoning functions.

Cheers,
Evren

>
>
> Thanks,
>
> Tim Swanson
> Semantic Arts, Inc.
> Fort Collins, Colorado
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> Pellet-users mailing list
> Pellet-users at lists.owldl.com
> http://lists.owldl.com/mailman/listinfo/pellet-users
> _______________________________________________
>
> Sponsored by Clark & Parsia, LLC http://clarkparsia.com/