Diego and Luis,
I am concerned that the MUO ontology you are proposing people adopt
has serious issues. I was reading
http://forge.morfeo-project.org/wiki_en/index.php/Units_of_measurement_ontology#Alternatives_to_represent_measurable_quantities_in_RDF
You refer to my Design Issues note on Interpretation properties but
you don't seem to have taken it into account.
You say, (I add the <> brackets you forgot from the N3 in the article)
:Spain :area [
muo:numericalValue "504782"^^xsd:double ;
muo:measuredIn :Sq_Km
] ;
:area [
muo:numericalValue "194897"^^xsd:double ;
muo:measuredIn :Sq_Miles
] .
But I would expect Spain to have, in principle, just one area. I would
expect :area to be a functional property. If Spain has one area,
then we get the confusion:
:Spain :area [
muo:numericalValue "504782"^^xsd:double ;
muo:measuredIn :Sq_Km;
muo:numericalValue "194897"^^xsd:double ;
muo:measuredIn <Sq_Miles>
] .
which is completely muddled an ambiguous of course.
I suppose you can avoid this using the extra arc as in
:Spain :area [
muo:expressableAs [
muo:numericalValue "504782"^^xsd:double ;
muo:measuredIn :Sq_Km
] ;
muo:expressableAs [
muo:numericalValue "194897"^^xsd:double ;
muo:measuredIn #Sq_Miles
] .
but that is cumbersome.
By contrast, the Interpretation Properties pattern, which you do not
review in your article at all, makes it much simpler.
:Spain :area [ :Sq_Km "504782"^^xsd:double].
By the way, in N3 you can write the above as
:Spain :area [ :Sq_Km 504782e0].
or even
:Spain :area 504782e0^:Sq_Km.
This does not have the problem above, as there is no issue with
:Spain :area 504782e0^:Sq_Km , 194897e0^:Sq_Miles .
that is
:Spain :area [ :Sq_Km 504782.0e+00 ];
:area [ :Sq_Miles 194897.0e+00 ] .
as the same area can be expressed using two different units.
Could you convert the MUO work to use interpretation properties?
Tim BL
