Re: SpatialThing and feature (again)

This could also be resolved by thinking of geo:long as a property that can
entail a geometry property of the feature - maybe its even a geometry
property in the same way that a 2D point is a partial representation of a
3D location?

Rob

On Thu, 20 Apr 2017 at 02:38 Joshua Lieberman <jlieberman@tumblingwalls.com>
wrote:

> Andreas,
>
> It may not be worth delving too deeply into this...
>
> W3C Basic Geo defines SpatialThing and then subclasses it to Point
> carrying the lat and long properties. No one defines their own
> SpatialThings, they simply add geo:lat and geo:long properties to some
> resource X to turn it into “also a Point”, in other words “also a
> geometry”. This implies for most users but does not actually assert that
> resource X is both a feature and a geometry. One could form a subclass of
> geo:SpatialThing that was actually disjoint with geo:Point or other
> geometry,  which would then align more-or-less with iso geosparql:Feature,
> hence the assertion that some geo:SpatialThings are geosparql:Features.
> This is largely hypothetical.
>
> There is a similar property in GeoRSS, the point(pos) property, but this
> doesn’t try to create one feature-geometry amalgam. It’s simply a shortcut
> for a longer expression that identifies some resource as a _Feature with a
> “where" object property connecting to a Point geometry resource.
>
> It might be most accurate to say that your example of using W3C Basic Geo
> to represent feature and geometry in the “style” of geosparql is actually
> the longhand of what people are trying to do when they do use geo:lat and
> geo:long, identifying a resource as a real world feature and giving it a
> closely allied point geometry.
>
> —Josh
>
> > On Apr 19, 2017, at 11:54 AM, Andreas Harth <harth@kit.edu> wrote:
> >
> > Hi,
> >
> > On 04/19/17 13:29, Joshua Lieberman wrote:
> >> My understanding based on the limited documentation is that
> w3cgeo:SpatialThing covers both features and models such as geometries, so
> >
> > that's my understanding too.  With the W3C WGS84 vocabulary you can
> write:
> >
> > @prefix geo: <http://www.w3.org/2003/01/geo/wgs84_pos#> .
> > @prefix : <#> .
> >
> > :bob a geo:SpatialThing ; geo:lat "52.5196143" ; geo:long "13.4065603" .
> >
> > So the resource with the URI :bob is both the "feature" and the
> "geometry".
> >
> > In other representations (NeoGeo, GeoSPARQL), you would identify two
> separate
> > resources:
> >
> > @prefix geo: <http://www.w3.org/2003/01/geo/wgs84_pos#> .
> > @prefix : <#> .
> >
> > :bob a :Feature ; :geometry _:bnode .
> > _:bnode a :Geometry , geo:Point ; geo:lat "52.5196143" ; geo:long
> "13.4065603" .
> >
> > The URI :bob now represents the "feature" resource, and the blank node
> _:bnode
> > represents the "geometry" resource.
> >
> > I wouldn't know how to write OWL axioms to map the two modeling choices
> though.
> >
> > Best regards,
> > Andreas.
> >
> >
>
>
>