[Pellet-users] How to use taxonomy computeLCA(...)?

[Evren Sirin]

On 4/14/08 11:52 AM, Andrea Della Corte wrote:
> Could u pls help me by making an example code?

This function is not meant to be part of the public functions. It is 
used internally for a specific purposes and known to cause problems in 
more general cases. So use it at your own risk ;) Below I give some 
information on how to use it but you might consider alternatives like 
the one provided in Jena [1]. Though I have not personally used the Jena 
function and I'm not sure if it does the same thing (Pellet returns a 
list of classes as LCA since there might not always be a unique LCA but 
I see that Jena function returns a single class. You might get help 
about the Jena function on the Jena mailing list).

>
> For example, given this ontology 
> http://protege.stanford.edu/plugins/owl/owl-library/koala.owl
>
> that has
>
> Thing
> |
>    Habitat
>    |
>    |_ Forest
>       |_ DryEucaliptForest
>       |_ RainForest
>
> How do i prepare the input "aterm.ATermList list" (how do i give 
> DryEucaliptForest and RainForest as input)?

Something along the lines of the following should work:

ATermAppl DryEucaliptForest = ATermUtils.makeTermAppl( namespace + 
"DryEucaliptForest" );
ATermAppl RainForest = ATermUtils.makeTermAppl( namespace + "RainForest" );
ATermList list = ATermUtils.makeList( new ATermAppl[] { 
DryEucaliptForest, RainForest  } );

kb.getTaxonomy().computeLCA( list );
>
> I should have as output Forest - Habitat - Thing.

No. LCA is the *lowest* common ancestor so in this example there is a 
single unique lowest ancestor which is Forect. I f you want to get all 
common ancestors then you need to get the super classes of LCA. LCA 
returns a list of classes only when the list elements have common 
ancestor classes that are not subsumed by each other.

HTH,
Evren

[1] 
http://jena.sourceforge.net/javadoc/com/hp/hpl/jena/ontology/OntTools.html#getLCA(com.hp.hpl.jena.ontology.OntModel,%20com.hp.hpl.jena.ontology.OntClass,%20com.hp.hpl.jena.ontology.OntClass)
>
> Thanks,
>
> Andrea
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> 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/