- From: Graham Klyne <gk@ninebynine.org>
- Date: Fri, 27 Feb 2004 17:42:02 +0000
- To: RDF interest group <www-rdf-interest@w3.org>, <www-rdf-logic@w3.org>
Hi,
I'm wondering what strategies folks are using for inference over
collections (lists) of values in RDF (other than resorting to ad-hoc
code). (Maybe also over containers, but the closure of lists makes the
problem easier to define.)
A simple example would be the selection of the maximum value from a list; e.g.
given:
_:weatherToday
:hourlyTemperatures
( "10"^^xsd:integer "12"^^xsd:integer "15"^^xsd:integer
"16"^^xsd:integer "14"^^xsd:integer "17"^^xsd:integer
"13"^^xsd:integer "12"^^xsd:integer "10"^^xsd:integer
"9"^^xsd:integer "7"^^xsd:integer "6"^^xsd:integer ) .
how to deduce:
_:weatherToday
:maxTemperature "17"^^xsd:integer .
A more complex example might be the extraction of a mean value given a list
of sample values and observed frequencies:
_:experiment
:samples ( _:s1 _:s2 _:s3 _:s4 ) .
_:s1 :value "10"^^xsd:integer ;
:freq "2"^^xsd:integer .
_:s2 :value "20"^^xsd:integer ;
:freq "5"^^xsd:integer .
_:s3 :value "30"^^xsd:integer ;
:freq "6"^^xsd:integer .
_:s4 :value "40"^^xsd:integer ;
:freq "3"^^xsd:integer .
to deduce:
_:experiment
_meanValue "26"^^xsd:integer
with access to normal arithmetic functions.
This can be done by generating intermediate resources that relate to
accumulated values from the list, but this approach rapidly becomes very
ugly. I have some half-baked ideas for a tidier approach, but was hoping
that someone might have a fully-baked solution.
#g
------------
Graham Klyne
For email:
http://www.ninebynine.org/#Contact
Received on Friday, 27 February 2004 12:42:24 UTC