I am trying to write a query
Hospitals and hasNameWithWords value "center"^^string
This query returns me the instances that has the hospitals that has "center" in its name in Protege 4.2 with FACT++ reasoner as well as Hermit reasoner
but when i input the same query in the OWL-API's DL Query Example thats available in the website
http://sourceforge.net/p/owlapi/code/ci/aef6981535f07a2d0d44c394b9f4d5415f36025a/tree/contract/src/test/java/org/coode/owlapi/examples/DLQueryExample.java
I don't get any result.
But it gives me result when i write simple queries such as
Hospitals
Is it because the reasoner in the code is not able to make the inference?
What other reasoner would be better?
The class you use as example (DLQueryExample.java) relies on an OWL-API built-in structural reasoner (OWLReasonerFactory reasonerFactory = new StructuralReasonerFactory();).
This type of reasoner is fairly simple and is not suited for complex queries as yours. It can however provide answers on the class hierarchy: This is why you get some results with the straightforward query Hospitals.
What you need to do is to set your code to either use Hermit or FACT++. I give the example with Hermit:
- Download HermiT jar file and add it to the class path of your project.
- In your class, replace the line
OWLReasonerFactory reasonerFactory = new StructuralReasonerFactory(); by: OWLReasonerFactory reasonerFactory = new Reasoner.ReasonerFactory();. You should have to import org.semanticweb.HermiT.Reasoner in order to make it work.
- We just replaced the default reasoner by HermiT. The rest of the code should stay the same and your query should now work.
- You could try FaCT++ and Pellet and compare speed, etc...
