My use case is executing the OWL (RL) test cases from Michael Schneider
et al. Basically they consist of two turtle files, one before and one
after inferencing. I run inferences (using SPIN) myself and then want to
check that all triples from Michael's conclusions file are found in the
SPIN inferences. The complication is that they are loaded from a
different Turtle file than the starting point of the inferences, and
therefore I cannot use bnode identifier comparison - they are different.
Anyway, I have for now gone with an approximation - turning bnodes into
wildcards at least checks the other nodes in those triples.
Thanks!
Holger
On 7/3/2012 3:40, Stephen Allen wrote:
On Mon, Jul 2, 2012 at 3:27 AM, Dave Reynolds <dave.e.reyno...@gmail.com> wrote:
On 02/07/12 11:07, Holger Knublauch wrote:
On 7/2/2012 18:47, Stephen Allen wrote:
On Mon, Jul 2, 2012 at 12:36 AM, Holger Knublauch
<hol...@knublauch.com> wrote:
Hi all,
I am aware of Graph.isIsomorphicWith, but I need a function that tests
whether Graph A is a sub-set of Graph B, including the ability to map
bnodes
into each other. Does that exist in Jena?
How about:
ask {
graph <A> { ?s ?p ?o }
minus { graph <B> { ?s ?p ?o } }
}
That may work for named nodes, but what about bnode structures such as
complex OWL class expressions? The bnode identity may be different in
both graphs, yet their patterns of co-existence need to be compared. A
triple-by-triple comparison will not be able to handle this correctly.
There's nothing built into Jena for this, as far as I know.
It's not trivial. Subgraph isomorphism is NP-Complete whereas graph
isomorphism (the job done by isIsomorphicWith) is (possibly) fractionally
easier - it is NP but (probably) not NP-Complete.
I'm not sure this will work, but if the following assumptions hold true:
1) the only independent blank nodes only come from inference
2) both graphs use the same entailment regime
3) inferences are additive only
Then you could run the minus query on the raw triples (ie
InfGraph.getRawGraph() ). Sometimes it isn't too hard to make 1) hold
if you use consistently generated URIs instead of blanknodes in your
application.
-Stephen
