Hi All.
I have found a Little problem in the implementation of GeoSPARQL. The problem is that Marmotta doesn't returns the spatial reference URI before WKT, as it is specified in the Geosparql Standard Document. Req 10 and Req 11. [1] Req 10 All RDFS Literals of type geo:wktLiteral shall consist of an optional URI identifying the coordinate reference system followed by Simple Features Well Known Text (WKT) describing a geometric value. Valid geo:wktLiterals are formed by concatenating a valid, absolute URI as defined in [RFC 2396], one or more spaces (Unicode U+0020 character) as a separator, and a WKT string as defined in Simple Features [ISO 19125-1]. Req 11 The URI <http://www.opengis.net/def/crs/OGC/1.3/CRS84> shall be assumed as the spatial reference system for geo:wktLiterals that do not specify an explicit spatial reference system URI Example: SPARQL Query PREFIX geo: <http://www.opengis.net/ont/geosparql#> Select ?wkt WHERE { ?r geo:hasGeometry ?geo. ?geo asWKT ?geo } limit 1 Marmotta response: wkt Point(-78.562245 26554456)^^http://www.opengis.net/ont/sf#wktLiteral But Marmotta should return:: wkt <http://www.opengis.net/def/crs/OGC/1.3/CRS84> Point(-78.562245 26554456)^^ http://www.opengis.net/ont/sf#wktLiteral This URI is important for applications that need to identify the reference system and show the data in a map, for example MAP4RDF (UPM).[2] and openMapsJS (UCUENCA). [3]. [1]. http://www.opengeospatial.org/standards/geosparql [2]. http://oeg-dev.dia.fi.upm.es/map4rdf/ [3]. https://github.com/marcelocaj/openmapjs 2016-03-23 10:15 GMT-05:00 fernando baculima <[email protected]>: > Hi Sergio. > > > So I think it would be good to put a suggestion in the WIKI > > or here > > [http://marmotta.apache.org/kiwi/geosparql.html] > > to help users of geosparql > > > > Cheers > > 2016-03-22 12:50 GMT-05:00 Sergio Fernández <[email protected]>: > >> Hi Fernando, >> >> On Tue, Mar 22, 2016 at 6:38 PM, Fernando Baculima < >> [email protected] >> > wrote: >> > >> > I am Fernando. >> > I followed and I have collaborated in implementing geosparql since its >> > beginnig. >> > >> >> Good to see you back. >> >> In the RDF, exists the following relation >> > http://geo.marmotta.es/ontology#hasExactGeometry is subPropertyOf >> > http://www.opengis.net/ont/geosparql#hasGeometry >> > Then marmotta should infer this relation. >> > >> > >> > To solve this problem. I implement the following rule in the reasoner >> > Module. >> > @prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> >> > ($1 <http://www.w3.org/2000/01/rdf-schema#subPropertyOf> $2), ($3 $1 >> $4) >> > -> ($3 $2 $4) >> > >> > Then my question is: >> > Is this process right for all geosparql users? >> > Is there other way for marmotta to infer this relation? >> > >> >> Yes, that's the expected behavior. The current KiWi SPARQL implementation >> only supports the RDF Entailment: >> https://www.w3.org/TR/sparql11-entailment/#RDFEntRegime but not further >> entailment such as RDFS, OWL or D-entailment. So the single way to get >> ssuch queries working as you expected is having a reasoner program >> materializing those inferences. >> >> Hope that helps. >> >> Cheers, >> > >
