Sorry, only just noticed this question. Responses below:
On 20/05/2020 10:41, Kenneth Keefe wrote:
Thanks for all the help so far! I've made some good progress on this
example I'm trying to forge. Here are the files for this example:
Ontology: https://cioi.iti.illinois.edu/ont/examples/roster.owl
Rules: https://cioi.iti.illinois.edu/ont/examples/roster.rules
Using this code:
OntModel model = ModelFactory.*createOntologyModel*(OntModelSpec.*OWL_MEM*);
model.read("file:roster.owl");
List<Rule> rules = Rule.*rulesFromURL*("file:roster.rules");
Reasoner reasoner = new GenericRuleReasoner(rules);
InfModel inf = ModelFactory.*createInfModel*(reasoner, model);
printAllStatements(inf);
I get this output (I use the LocalName for the predicates and objects for
readability):
b04230c7-55dc-4e08-92d7-26559c0c478f hasLastName "Smith" .
c33de24f-82f1-4aa2-a78e-73201341b274 type Person .
c812ff54-30bf-49e7-8e35-3544dad096b7 hasFirstName "Sally" .
16b7a887-2fb9-4bdb-a529-34ca8b3137e4 hasFirstName "Bob" .
b31eb7d5-a8ad-469e-ae83-366bdf46fd72 hasLastName "Jones" .
8b46f0c7-4eb2-41e2-8789-8967e8f63eec type Person .
http://example.com/ont/roster/ versionIRI .
http://example.com/ont/roster/ type Ontology .
http://example.com/ont/roster/RosterEntry type Class .
http://example.com/ont/roster/bobEntry hasSignature "Bob Smith" .
http://example.com/ont/roster/bobEntry type RosterEntry .
http://example.com/ont/roster/bobEntry type NamedIndividual .
http://example.com/ont/roster/Person type Class .
http://example.com/ont/roster/hasLastName range string .
http://example.com/ont/roster/hasLastName domain Person .
http://example.com/ont/roster/hasLastName type DatatypeProperty .
http://example.com/ont/roster/sallyEntry hasSignature "Sally Jones" .
http://example.com/ont/roster/sallyEntry type RosterEntry .
http://example.com/ont/roster/sallyEntry type NamedIndividual .
http://example.com/ont/roster/hasSignature range string .
http://example.com/ont/roster/hasSignature domain RosterEntry .
http://example.com/ont/roster/hasSignature type DatatypeProperty .
http://example.com/ont/roster/hasFirstName range string .
http://example.com/ont/roster/hasFirstName domain Person .
http://example.com/ont/roster/hasFirstName type DatatypeProperty .
Here are my questions:
Focusing on just the Bob Smith entry:
b04230c7-55dc-4e08-92d7-26559c0c478f hasLastName "Smith" .
c33de24f-82f1-4aa2-a78e-73201341b274 type Person .
16b7a887-2fb9-4bdb-a529-34ca8b3137e4 hasFirstName "Bob" .
1. Are these unique ids of anonymous nodes?
Yes.
2. Why are they not identical across these three lines?
Because your ?y variable hasn't been bound in the rule body, each triple
pattern finds there's no value for ?y and separately treats it as a bNode.
If you want a shared bNode then use makeTemp(?y) in the body (or
makeSoklem).
3. Is there a way to name these new nodes in the rule? For example, make
the new node http://example.com/ont/roster/people/BobSmith.
Sure, use uriConcat, something like (untested):
uriConcat('http://example.com/ont/roster/people/', ?first, ?last,
?y) -> ...
Dave
Thank you!
Ken
On Tue, May 12, 2020 at 1:44 AM Lorenz Buehmann <
buehm...@informatik.uni-leipzig.de> wrote:
Hi,
I think the rule would be basically
[r1: (?x rdf:type ex:RosterEntry), (?x ex:hasSignature ?sig),
regex(?sig, '(.*) (.*)', ?first, ?last) -> (?x ex:hasFirstName
?first), (?x ex:hasLastName ?last), (?x rdf:type ex:Person) ) ]
Note, it's untested and you have to define your prefix ex: in the rules
file. You might also have to adapt the regex pattern to cover different
white space chars.
On 12.05.20 00:56, Kenneth Keefe wrote:
I am pretty new to using Jena and OWL. I have read many great tutorials
regarding RDF and OWL. The focus of those tutorials has largely been how
to
structure the ontology and define restrictions on properties and such.
However, I have not been able to find good tutorials that explain how
inference is done and how I can define my own inference rules. I'm
wondering if I am simply not searching for the right thing.
Regardless, here is a significant example that I think will really help
me
get started with inference using Jena. I created a minimal example to
enable discussion. Here is a pastebin: https://pastebin.com/ScTGcbcZ
The ontology has two classes, RosterEntry and Person and three data
properties, Signature (associated with RosterEntry), and FirstName and
LastName (both associated with Person). The example also has two
RosterEntry individuals with signatures of "Bob Smith" and "Sally Jones."
I would like to write a rule that causes Jena to infer the following new
facts:
<owl:Individual>
<rdf:type
rdf:resource="http://example.com/ont/roster/Person"; />
<hasFirstName>Bob</hasFirstName>
<hasLastName>Smith</hasLastName>
</owl:Individual>
<owl:Individual>
<rdf:type
rdf:resource="http://example.com/ont/roster/Person"; />
<hasFirstName>Sally</hasFirstName>
<hasLastName>Jones</hasLastName>
</owl:Individual>
How do I do that? Full answers or nudges in the right direction are both
very welcome. Thank you!
Ken
