Hi Christoph, On Dec 7, 2009, at 7:29 AM, Christoph wrote:
> I like to use Allegrograph together with Topbraid Composer. > Allegrograph suggests to store latitude and longitude not in seperate > triples but for example, using ISO6709: > <http://ex.com#HQ> <geo:isAt> "+37.45-123.27"^^<geo:ISO6709> . > > How is this supported within Topbraid Composer, which provides support > for WGS84 encodings through the WGS84_pos.owl file - but here, the > latitude/longitude are stored seperately... it is possible to define new datatypes with TBC (make sure to have 3.2.1 for the latest OWL 2 support). However, the current forms interface will only allow you to enter values in the standard datatype values such as xsd:string. See for example the attached file. Whenever you add a value on geo:isAt it will make xsd:string literals. In order to cast them to another datatype, run a SPARQL query such as MODIFY DELETE { ?subject geo:isAt ?oldValue . } INSERT { ?subject geo:isAt ?newValue . } WHERE { ?subject geo:isAt ?oldValue . LET (?newValue := smf:cast(?oldValue, geo:ISO6709)) } Existing geo:isAt values are handled Ok though, so the inconvenience above only concerns new data that is manually entered. All this is unrelated from the W3 geo ontology bundled with TBC, which follows an alternative encoding. You could also use that and then create some SPARQL or SPIN mapping that copies the values from the geo:lat/long properties into a concatenated ISO string. This would allow you to easier make use of the map features built into TBC. > > If I create a new Allegrograph Database within Topbraid Composer, is > there a way to set indexes directly within Tobraid Composer or do I > have to set them afterwards manually? Such low-level AG features need to be configured using AG tools. Sorry. > Moerover, how can I define the > geospatial subtypes (http://www.franz.com/agraph/allegrograph/doc/ > geospatial-tutorial.html#header2-24) - is this only possible within > SPARQL queries? SPARQL is definitely one option, for example using SPIN's Magic Properties or user-defined SPARQL functions: Composing the Semantic Web: Magic Properties with SPIN These can be used to do various kinds of geospatial operations, although their performance might suffer if a lot of data crunching is needed. Holger -- You received this message because you are subscribed to the Google Groups "TopBraid Composer Users" group. To post to this group, send email to topbraid-composer-us...@googlegroups.com. To unsubscribe from this group, send email to topbraid-composer-users+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/topbraid-composer-users?hl=en.
geoTest.n3
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