Re: Sub-properties for locn:geometry? (was: RE: ISA Core Location Vocabulary)

On 2014-01-17 18:28, Sven Schade wrote:
>
> > Absolutely. So we should agree if we need such an additional element, 
> which would make the overall vocabulary more complex, i.e. less simple 
> and adoptable.
>
> > We might try to answer the following three (subsequent) questions:
>
>    > 1) What would be a use case for which we would need a feature (or 
> similar) class?
>
> >>If that class exists, we can attach properties to it. Properties that 
> already exist in the vocabulary, like geometry, address or name. From 
> a consumers' perspective: If a thing is designated as being a spatial 
> thing, one can expect that it might have certain characteristics, like 
> an address, a geographical name,  a geometry. That is useful.
>
> >>Regarding the new properties proposed by John: Let's assume a spatial 
> feature like a city. It could have tens of different geometries. I 
> think that in most cases a user agent will be interested in the 
> centroid or MBR of the city (the feature), not of all the different 
> geometries. Although I can also imagine that a user agent does want to 
> get the centroid or MBR of a particular geometry. So I think the new 
> properties could be properties of both spatial features and geometries.
>
> Following John’s suggestion the “Location” class would basically gain 
> all the capabilities that you are requesting above, i.e. back to 
> question (2) I am missing a central point here?
>
>       > 2) Why could this use case not be realized with the more
>     light-weight model that was initially suggested by John?
>

It could very well  be that I am overlooking something. But let me try 
to explain my thinking:  The original suggestion was to model centroid, 
MBR, etc. as subproperties of locn:geometry. But the range of 
locn:geometry is locn:Geometry. So I think you can't say something like:

ex:London
     a locn:Location;
     locn:centroid ex:aCentroid;
     locn:mbr ex:aMbr;
     locn:geometry ex:goemetry1;
     locn:geometry ex:geometry2;
     locn:geometry ex:geometry3.

This is assuming that locn:Location is more or less the same as a 
spatial feature, which is something I only began to realize very 
recently :-)

Regards,
Frans