Reformulate Point (subclass of Geometry)

[dr-shorthair]

Following on from #659 here is a proposal to introduce a new class geo:Point with property geo:hasPosition as follows:

###  http://www.opengis.net/ont/geosparql#Point
geo:Point
    a owl:Class ;
    rdfs:subClassOf geo:Geometry ; 
    rdfs:subClassOf [ 
      a owl:Restriction ; 
      owl:onProperty geo:hasPosition ; 
      owl:cardinality "1"^^xsd:nonNegativeInteger ;
    ] ;
    skos:prefLabel "Point"@en ;
    skos:definition "A geometry consisting of a single Point"@en ;
.

###  http://www.opengis.net/ont/geosparql#hasPosition
geo:hasPosition
  a owl:DatatypeProperty ;
  rdfs:domain geo:Point ;
  rdfs:subPropertyOf geo:hasSerialization ;
  skos:definition "The coordinate poistion of a point."@en ;
  skos:prefLabel "has position"@en ;
  skos:scopeNote "The value is a literal that is a point serialization"@en ;
.

[situx]

@dr-shorthair We have a class sf:Point in the simple features vocabulary which is a subclass of geo:Geometry.

sf:Point
    a
        rdfs:Class ,
        owl:Class ;
    rdfs:isDefinedBy <http://www.opengis.net/ont/sf> ;
    rdfs:subClassOf sf:Geometry ;
    skos:definition """A Point is a 0-dimensional geometric object and represents a single location in coordinate space. 
A Point has an x-coordinate value, a y-coordinate value. If called for by the associated Spatial Reference System, it may also have coordinate values for z and m.
The boundary of a Point is the empty set."""@en ;
    skos:prefLabel "Point"@en ;
.

Is that what you need?

The only difference I can see is that there is no property "hasPosition". We only have geo:hasGeometry

[dr-shorthair]

Thanks @situx - yes, that does go most of the way.
Note that, hasPosition is a sub-property of hasSerialization not hasGeometry.

hasGeometry has domain Feature.
hasSerialization has domain Geometry.

hasPosition has tighter semantics than hasSerialization: the value must encode a single point position.

[situx]

You are right, hasPosition should be a subproperty of hasSerialization. What is its range?
A geometry literal like in hasSerialization?

[dr-shorthair]

Yes, a geometry literal, but restricted to one describing a single position, e.g. WKT POINT.
(I don't think that restriction can be easily expressed in OWL.)

[dr-shorthair]

sf:minimum & sf:maximum (properties of sf:Envelope) should be sub-properties of hasPosition #659