Ah, we don't have SIS_DATA installed. I'll set it up and let you know how it goes.
Our prefixes are the following: PREFIX geo: <http://www.opengis.net/ont/geosparql#> PREFIX geof: <http://www.opengis.net/def/function/geosparql/> PREFIX uom: <http://www.opengis.net/def/uom/OGC/1.0/> PREFIX skos: <http://www.w3.org/2004/02/skos/core#> PREFIX site: <https://dkglab.github.io/ns/for/site/> Thanks again for the help, Sychic On Sat, Feb 15, 2025 at 5:40 PM Simon Bin <[email protected]> wrote: > Did you install SIS_DATA? > > > https://jena.apache.org/documentation/geosparql/geosparql-fuseki.html#sis_data-environment-variable > > Are your prefixes correct? You did not include them in your query > example. > > Here is a link to the AKSW Jena geosparql demo endpoint with your > query: > > https://api.triplydb.com/s/CZhLntVur > > Click on table to see the table result and on Geo to see the geo > rendering. > > Cheers, > > On Sat, 2025-02-15 at 12:58 -0500, Sychic wrote: > > This appears to still yield an empty row for me, my query now looks > > like > > this: > > SELECT ?bufferGeom > > WHERE { > > BIND( > > geof:buffer( > > "<http://www.opengis.net/def/crs/EPSG/0/3305> > > POINT(199247.73091 > > 8059595.711024)"^^geo:wktLiteral, > > 500, > > uom:kilometer > > ) AS ?bufferGeom > > ) > > } > > > > and my output is: > > -------------- > > > bufferGeom | > > ============== > > > | > > -------------- > > Not sure what's going wrong here, I can share more about my setup if > > that > > helps: I'm using a Jena Fuseki server with Geosparl extensions to > > load my > > dataset and RSPARQL as my jena client. > > > > On Sat, Feb 15, 2025 at 5:51 AM Simon Bin > > <[email protected]> > > wrote: > > > > > Hi Sychic, > > > > > > Try specifying the CRS: > > > > > > BIND( > > > geof:buffer( > > > "<http://www.opengis.net/def/crs/EPSG/0/3305> > > > POINT(199247.73091 > > > 8059595.711024)"^^geo:wktLiteral, > > > 500, > > > uom:kilometer > > > ) AS ?bufferGeom > > > ) > > > > > > Cheers, > > > > > > On Fri, 2025-02-14 at 12:55 -0500, Sychic wrote: > > > > Hello, > > > > I'm writing asking for some help with using `geo:buffer` and > > > > `geo:distance`. I'm working with a dataset using the EPSG 3305 > > > > CRS > > > > and I'm > > > > trying to use geo:buffer to find subjects in the dataset which > > > > are > > > > within a > > > > circular area of a given point. Unfortunately it appears the > > > > below > > > > query > > > > returns no results. > > > > ```sparql > > > > SELECT ?feature ?label ?wkt > > > > WHERE { > > > > ?feature skos:prefLabel ?label ; > > > > geo:hasGeometry ?geometry . > > > > ?geometry geo:asWKT ?wkt . > > > > > > > > BIND( > > > > geof:buffer( > > > > "POINT(-5.016805 36.888297)"^^geo:wktLiteral, > > > > 500, > > > > uom:kilometer > > > > ) AS ?bufferGeom > > > > ) > > > > > > > > FILTER( > > > > geof:sfIntersects(?wkt, ?bufferGeom) > > > > ) > > > > } > > > > ``` > > > > I initially thought the issue may have been with my buffer > > > > declaration and > > > > upon further inspection, it seems like there was. The following > > > > select > > > > statement yields an empty line: > > > > ```sparql > > > > SELECT ?bufferGeom > > > > WHERE { > > > > BIND( > > > > geof:buffer( > > > > "POINT(0 0)"^^geo:wktLiteral, > > > > 500, > > > > uom:meter > > > > ) AS ?bufferGeom > > > > ) > > > > } > > > > ``` > > > > I then pivoted to trying to use geo:distance to see if that would > > > > work too, > > > > however this query also returns nothing: > > > > ```sparql > > > > SELECT ?dist > > > > WHERE { > > > > BIND( > > > > geof:distance( > > > > "POINT(0 0)"^^geo:wktLiteral, > > > > "POINT(0 1)"^^geo:wktLiteral, > > > > uom:meter > > > > ) AS ?dist > > > > ) > > > > } > > > > ``` > > > > I'm using Jena Fuseki Geosparql 5.3.0 to load my data and Apache > > > > Jena > > > > 5.3.0 > > > > to execute my SPARQL queries. > > > > Hoping for some assistance, > > > > Sychic > > > > > > > > > > > >
