Re: [Bigdata-developers] Geonames and Blazegraph Geospatial index

[Michael S. <ms...@me...>]

Hi Jem,

we are aware of this limitation and have been discussing this use case previously, but (as you guessed) indexing of such “distributed” coordinates is currently not implemented. So for now there’s no way around the transformation (you may, however, want to consider deleting the single-component literals when creating the composed literals, if that’s an option for you). 

As a side note: there are also standards-based binary coordinate formats in which you could transform the literals. For instance, Wikidata is using WKT literals, see the POINT datatype in https://en.wikipedia.org/wiki/Well-known_text, which could easily be used in combination with a customer geospatial LiteralSerializer.

Best,
Michael

> On 25 Jul 2016, at 17:14, Jem Rayfield <jem...@ft...> wrote:
> 
> I guess I could invoke a sparql update as follows:
> 
> INSERT {
>   ?s <http://jems/latlong <http://jems/latlong>> ?latlong
> }
> WHERE { 
>  ?s <http://www.w3.org/2003/01/geo/wgs84_pos#lat <http://www.w3.org/2003/01/geo/wgs84_pos#lat>> ?lat ;
>     <http://www.w3.org/2003/01/geo/wgs84_pos#long <http://www.w3.org/2003/01/geo/wgs84_pos#long>> ?long .
>  BIND(STRDT(STR(CONCAT(?lat, "#", ?long)), <http://jems/custom/latlong/literaltype <http://jems/custom/latlong/literaltype>>) AS ?latlong)
> }
> 
> However this will create many millions of essentially redundant statements?
> 
> Question, re: multiple predicate index still stands.
> 
> Cheers
> Jem
> 
> 
> On 25 July 2016 at 15:14, Jem Rayfield <jem...@ft... <mailto:jem...@ft...>> wrote:
> Hello,
> 
> I would like to index geonames lat/long using Blazegraphs geospatial index.
> 
> Geonames lat/longs are provided in the following flavour of RDF:
> 
> <http://sws.geonames.org/4667981/ <http://sws.geonames.org/4667981/>> <http://www.w3.org/2003/01/geo/wgs84_pos#lat <http://www.w3.org/2003/01/geo/wgs84_pos#lat>> "35.79787" .
> <http://sws.geonames.org/4667981/ <http://sws.geonames.org/4667981/>> <http://www.w3.org/2003/01/geo/wgs84_pos#long <http://www.w3.org/2003/01/geo/wgs84_pos#long>> "-83.44683" .
> 
> I was wondering if anyone has already worked on Custom Geospatial Data types, vocabularies etc for Geonames in Blazegraph ?
> 
> 
> It appears that one would need flatten the objects into a single multidimensional literal for indexing?
> 
> <http://sws.geonames.org/4667981/ <http://sws.geonames.org/4667981/>> somenamespace:latlong "35.79787#-83.44683"
> 
> With the configuration and definition of a new literal type?
> 
> I am wondering if its possible to index on multiple known predicates rather than multidimensional literals with extended data types?
> 
> 
> Cheers
> -- 
> Jem Rayfield
> Head of Solution Architecture
> Technology
> 
> +44 (0)7709 332482 <tel:%2B44%20%280%297709%20332482>
> Number One Southwark Bridge, London SE1 9HL
> 
> 
> 
>  <https://www.facebook.com/financialtimes> <https://twitter.com/FT> <http://www.linkedin.com/company/financial-times> <https://plus.google.com/+FinancialTimes/posts> <http://www.youtube.com/user/FinancialTimesVideos>
> 
> 
> -- 
> Jem Rayfield
> Head of Solution Architecture
> Technology
> 
> +44 (0)7709 332482
> Number One Southwark Bridge, London SE1 9HL
> 
> 
> 
>  <https://www.facebook.com/financialtimes> <https://twitter.com/FT> <http://www.linkedin.com/company/financial-times> <https://plus.google.com/+FinancialTimes/posts> <http://www.youtube.com/user/FinancialTimesVideos>
> This email was sent by a company owned by Financial Times Group Limited ("FT Group <http://aboutus.ft.com/corporate-information/#axzz3rajCSIAt>"), registered office at Number One Southwark Bridge, London SE1 9HL.  Registered in England and Wales with company number 879531. This e-mail may contain confidential information. If you are not the intended recipient, please notify the sender immediately, delete all copies and do not distribute it further.  It could also contain personal views which are not necessarily those of the FT Group.  We may monitor outgoing or incoming emails as permitted by law.
> 
> ------------------------------------------------------------------------------
> What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic
> patterns at an interface-level. Reveals which users, apps, and protocols are 
> consuming the most bandwidth. Provides multi-vendor support for NetFlow, 
> J-Flow, sFlow and other flows. Make informed decisions using capacity planning
> reports.http://sdm.link/zohodev2dev_______________________________________________
> Bigdata-developers mailing list
> Big...@li...
> https://lists.sourceforge.net/lists/listinfo/bigdata-developers