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
