You are viewing a plain text version of this content. The canonical link for it is here.
Posted to users@jena.apache.org by Paul <pa...@proxml.be> on 2015/06/24 18:50:39 UTC
Well known Text in Spatial Search
Hello,
One of the builtin geo predicates is ogc:asWKT
e.g.
@prefix ogc: <http://www.opengis.net/ont/geosparql#> .
:node1000032677 a :Geometry ;
ogc:asWKT "POINT(7.338818000000001 51.4433324)"^^ogc:wktLiteral .
A WKT literal however can start optionally with an identifier for a coordinate system different from WGS 84.
e.g.
ogc:asWKT "<http://www.opengis.net/def/crs/EPSG/0/31370> POINT(142850.0 228850.0)"^^ogc:wktLiteral;
However Spatial Search seems to choke over this identifier.
Is ogc:asWKT limited to the default WGS 84 only within Spatial Search?
Paul
Kind Regards,
Paul Hermans
-------------------------
ProXML bvba
Linked Data services
KBO: http://data.kbodata.be/organisation/0476_068_080#id
(w) www.proxml.be
(e) paul@proxml.be
(tw) @PaulZH
(t) +32 15 23 00 76
(m) +32 473 66 03 20
OpenCube – Linked Open Statistical Data - http://opencube-project.eu/
Re: Well known Text in Spatial Search
Posted by Andy Seaborne <an...@apache.org>.
On 24/06/15 17:50, Paul wrote:
> Hello,
>
> One of the builtin geo predicates is ogc:asWKT
> e.g.
> @prefix ogc: <http://www.opengis.net/ont/geosparql#> .
> :node1000032677 a :Geometry ;
> ogc:asWKT "POINT(7.338818000000001 51.4433324)"^^ogc:wktLiteral .
> A WKT literal however can start optionally with an identifier for a coordinate system different from WGS 84.
> e.g.
> ogc:asWKT "<http://www.opengis.net/def/crs/EPSG/0/31370> POINT(142850.0 228850.0)"^^ogc:wktLiteral;
>
> However Spatial Search seems to choke over this identifier.
>
> Is ogc:asWKT limited to the default WGS 84 only within Spatial Search?
As far as I know, optionally coordinate systems are not supported, (the
source code would confirm or deny that) and I don't think there is the
capability to do coordinate transformation.
Jena uses JTS for WKT : the grammar shown does not have a coordinate
system:
http://tsusiatsoftware.net/jts/javadoc/com/vividsolutions/jts/io/WKTReader.html
Andy
>
>
> Paul
>
> Kind Regards,
> Paul Hermans
>
> -------------------------
> ProXML bvba
> Linked Data services
> KBO: http://data.kbodata.be/organisation/0476_068_080#id
> (w) www.proxml.be
> (e) paul@proxml.be
> (tw) @PaulZH
> (t) +32 15 23 00 76
> (m) +32 473 66 03 20
>
>
> OpenCube – Linked Open Statistical Data - http://opencube-project.eu/
>
>
>
>
>
>