[Pellet-users] how to fetch individuals with certain properties

Matthew Horridge matthew.horridge at cs.man.ac.uk
Mon Jun 9 18:47:04 UTC 2008 

Hi Alex,

I think you also might be able to get the individuals by asking for  
instances of "hasTag some rdfs:Literal"....  rdfs:Literal is the top  
datatype.  To do this in the OWL API you can create an  
OWLDataSomeRestriction with the property hasTag and a filler of  
rdfs:Literal which you can get from the data factory using  
getTopDatatype.  You can then ask Pellet (via the OWLReasoner  
interface) for instances of this restriction.

Cheers,

Matthew


On 9 Jun 2008, at 19:05, Alexander Becker wrote:

> Hi!
>
> Thats right, I don't care exactely what is contained in the hasTag  
> property, I just want to see if there is any hasTag property defined.
>
> But even if I name the OWLConstant to one of the individuals I have  
> in the ontology (as seen in {hasTag=["NPM"^^string],  
> hasTier=["pos"^^string]}m so I name it "NPM"), I don't get any  
> results.
>
> Again, my code so far:
> [code]
> @Test
> 	/**
> 	 * Fetch some individuals with certain properties.
> 	 */
> 	public void proptest() {
> 		OWLDataFactory factory =  
> OWLManager.createOWLOntologyManager().getOWLDataFactory();
> 		OWLDataProperty dataprop =  
> factory.getOWLDataProperty(URI.create(url + "#hasTag"));
> 		
> 		OWLDataType stringDataType = factory.getOWLDataType(URI.create("http://www.w3.org/2001/XMLSchema#string 
> "));
> 		OWLConstant constant = factory.getOWLTypedConstant("NPM",  
> stringDataType);
>
>        //OWLConstant constant = factory.getOWLUntypedConstant("NPN");
> 		OWLRestriction restriction =  
> factory.getOWLDataValueRestriction(dataprop, constant);
> 		
> 		Set<OWLIndividual> rv = reasoner.getIndividuals(restriction, true);
> 		
> 		System.out.println(rv);
> 	}
> [/code]
>
>
> HTH, Alex
>
> PS: Thanks for the for loop thing. It reminds me of Perl, so I like  
> it :)
>
> -------- Original-Nachricht --------
>> Datum: Mon, 9 Jun 2008 18:45:09 +0100
>> Von: "robert davey \\(JIC\\)" <robert.davey at bbsrc.ac.uk>
>> An: "Alexander Becker" <trennung at weinenvorglueck.de>
>> Betreff: RE: RE: [Pellet-users] how to fetch individuals with  
>> certain properties
>
>> I'm guessing it's because you are looking for the hasTag property,  
>> filled
>> with "test" as the typed constant datavalue. Unless a data property  
>> is in
>> your ontology that has this value and is referenced to an  
>> individual, you
>> won't get any results back.  I presume you are looking for all  
>> individuals
>> that have _any_ value in the hasTag property?
>>
>> As an aside, I see you're using java 1.5 (with generics), so you  
>> can use
>> the nice for loop function instead of an iterator. As you have  
>> typed the
>> all_ind set to OWLIndividual, so:
>>
>> Iterator ii = all_ind.iterator(); // ii = individual iterator
>> 		while( ii.hasNext() ) {
>> 			OWLIndividual ind = (OWLIndividual) ii.next();
>>
>> becomes:
>>
>> for (OWLIndividual i : all_ind)
>>
>> and you can do away with the casting as a result too.
>>
>> Hope this helps,
>>
>> Rob
>>
>> -----Original Message-----
>> From: Alexander Becker [mailto:trennung at weinenvorglueck.de]
>> Sent: Mon 6/9/2008 6:04 PM
>> To: robert davey (JIC)
>> Subject: Re: RE: [Pellet-users] how to fetch individuals with certain
>> properties
>>
>> Hi Rob,
>>
>> thanks for the exapmle and the link. I didn't found that one.
>> But now, after knowing how the way to use those things, I'm stuck  
>> with
>> fetching the properties.
>>
>> I can get them from a known individual this way:
>> [code]
>>    @Test // it's a junit test case that i abuse to test small  
>> pieces of
>> code
>> 	/**
>> 	 * Show the properties of an individual.
>> 	 */
>> 	public void get_props() {
>> 		Set<OWLIndividual> all_ind = reasoner.getIndividuals();
>> 		
>> 		System.out.println("individual count: " + all_ind.size());
>> 		
>> 		Iterator ii = all_ind.iterator(); // ii = individual iterator
>> 		while( ii.hasNext() ) {
>> 			OWLIndividual ind = (OWLIndividual) ii.next();
>> 			
>> 			Map<OWLDataProperty,Set<OWLConstant>> props =
>> reasoner.getDataPropertyRelationships(ind);
>> 			
>> 			System.out.println(props.toString());
>> 			break;
>> 		}
>> 		
>> 	}
>> [/code]
>>
>> The output is:
>> [quote]
>> individual count: 417
>> {hasTag=["NPM"^^string], hasTier=["pos"^^string]}
>> [/quote]
>>
>> And now, I want to do it the other way, fetch some Individuals that  
>> have a
>> property:
>> [code]
>> 	@Test
>> 	/**
>> 	 * fetch some individuals with certain properties.
>> 	 */
>> 	public void proptest() {
>> 		OWLDataFactory factory =
>> OWLManager.createOWLOntologyManager().getOWLDataFactory();
>> 		OWLDataProperty dataprop =
>> factory.getOWLDataProperty(URI.create(ontURI.toString() +  
>> "#hasTag"));
>> 		
>> 		OWLDataType stringDataType =
>> factory.getOWLDataType(URI.create("http://www.w3.org/2001/XMLSchema#string 
>> "));
>> 		
>> 		OWLConstant constant = factory.getOWLTypedConstant("test",
>> stringDataType);
>> 		OWLRestriction restriction =
>> factory.getOWLDataValueRestriction(dataprop, constant);
>> 		
>> 		Set<OWLIndividual> rv = reasoner.getIndividuals(restriction, true);
>> 		
>> 		System.out.println(rv);
>> 	}
>> [/code]
>>
>> But that doesn't work as I get an empty set as resut (output = "[]").
>>
>> So, where is my mistake?
>>
>> Cheers, Alex
>>
>> -------- Original-Nachricht --------
>>> Datum: Sun, 8 Jun 2008 17:14:51 +0100
>>> Von: "robert davey \\(JIC\\)" <robert.davey at bbsrc.ac.uk>
>>> An: trennung at weinenvorglueck.de, pellet-users at lists.owldl.com
>>> Betreff: RE: [Pellet-users] how to fetch individuals with certain
>> properties
>>
>>> Hi Alex,
>>>
>>> You can create OWLDescriptions from any implementing class, such as
>>> OWLRestriction:
>>>
>>> OWLDataFactory factory =
>>> OWLManager.createOWLOntologyManager().getOWLDataFactory();
>>> OWLDataProperty dataprop =
>>> factory.getOWLDataProperty("http://ontology/uri#hasTag");
>>> OWLConstant constant = factory.getOWLTypedConstant("test",
>>> "http://www.w3.org/2001/XMLSchema#string");
>>> OWLRestriction restriction =
>> factory.getOWLDataValueRestriction(dataprop,
>>> constant);
>>>
>>> I'm pretty sure there are some examples of how to do this in the  
>>> OWLAPI
>>> examples...
>>>
>>>
>> http://owlapi.svn.sourceforge.net/viewvc/owlapi/owl1_1/trunk/examples/src/main/java/org/coode/owlapi/examples/Example7.java
>>>
>>> Cheers
>>>
>>> Rob
>>>
>>> ---------------------------------------
>>> Dr. Rob Davey
>>> NCYC / Institute of Food Research
>>> Computational Biology / John Innes Centre
>>> Norwich Research Park
>>> Norwich, Norfolk, NR4 7HU
>>>
>>> Tel IFR : +44 (0)1603 251449 / x1449
>>> Tel JIC : +44 (0)1603 450833 / x2833
>>> Web     : http://cbr.jic.ac.uk/dicks/
>>> ---------------------------------------
>>>
>>>
>>>
>>> -----Original Message-----
>>> From: pellet-users-bounces at lists.owldl.com on behalf of
>>> trennung at weinenvorglueck.de
>>> Sent: Sat 6/7/2008 4:55 PM
>>> To: pellet-users at lists.owldl.com
>>> Subject: [Pellet-users] how to fetch individuals with certain  
>>> properties
>>>
>>> Hello!
>>>
>>> I want to get all individuals, that have some properties.
>>> They must have one of these: hasTag, startswith or endswith.  
>>> hasTag is
>> an
>>> OWLDataProperty, as I get (with some others) via:  
>>> Set<OWLDataProperty>
>>> my_dprops = reasoner.getDataProperties();
>>>
>>> Is it possible, to create an OWLDescription and get all matching
>>> individuals
>>> like that:
>>> [code]
>>> OWLDescription clsC = new OWLDescription(); // OWLDescription is
>> abstract,
>>> doesn't work that way.
>>>
>>>        // public Set<OWLIndividual> getIndividuals(OWLDescription  
>>> clsC,
>>> boolean direct)
>>>        Set<OWLIndividual> results = reasoner.getIndividuals(clsC,
>> false);
>>> [/code]
>>>
>>> If so, my primary question is: how do I create the OWLDescription?
>>>
>>> best regards, Alex
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>>
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