Documentation for geospatial queries

s.ar...@geophy.com

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Dec 13, 2016, 12:18:40 PM12/13/16

to Stardog

Would you have a more detail documentation describing the semantics of the geo function mentioned in the stardog website.

"... The operators supported by Stardog are geof:relate, geof:distance, geof:within, geof:nearby and geof:area. "

Something similar to:

https://jena.apache.org/documentation/query/spatial-query.html#property-function-library

It is very hard to guess the parameters for these functions.

Zachary Whitley

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Dec 13, 2016, 12:54:54 PM12/13/16

to Stardog

Check out http://www.opengeospatial.org/standards/geosparql#downloads

Starts on the page labeled 20. (page 38 of the pdf) yeayyyyy pdfs!

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Stephen Nowell

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Dec 13, 2016, 2:49:58 PM12/13/16

to sta...@clarkparsia.com

Hi,

You are right that our documentation is a bit...sparse in that area. I've created a ticket to update it for a future release.

In the meantime, here is a brief rundown of what each function does and its signature(s):

geof:relate

Returns the relationship between two geo features. Will be one of:

geo:equals, geo:within, geo:contains, geo:intersects, geo:disjoint

Examples:

As BGP: { ?relation geof:relate (?featureA ?featureB) }
FILTER (geof:relate(?featureA ?featureB geo:contains))

geof:distance

Returns the distance between two points in a given unit of measurement
Examples:

As BGP: { ?distance geof:distance (?point1 ?point2 < http://qudt.org/vocab/unit#desiredUnit>) }
BIND (geof:distance(?point1 ?point2 <http://qudt.org/vocab/unit#desiredUnit>) as ?distance)
FILTER (geof:distance(?point1 ?point2 <http://qudt.org/vocab/unit#Meter>) < 50)

geof:within

Returns all geo features within a given shape
Examples:

As BGP: { ?feature geof:within ?shape }
FILTER (geof:within(?feature, ?shape))

NOTE: ?shape in this case can be defined one of 4 ways:

?aGeoShape
(?aLowerLeftPoint, ?anUpperRightPoint)
(?aMinLatitude, ?aMinLongitude, ?aMaxLatitude, ?aMaxLongitude)
A JTS Polygon

geof:nearby

Returns all geo features within a given radius of a Point
Examples:

As BGP: { ?feature geof:nearby (?aPoint ?aNumber <http://qudt.org/vocab/unit#desiredUnit>) }
Alternative: { ?feature geof:nearby (?aLatitude ?aLongitude ?aNumber <http://qudt.org/vocab/unit#desiredUnit>) }

geof:area

Returns the area of a given geo feature in a given unit of measurement
Examples:

As BGP: { ?area geof:area (?feature <http://qudt.org/vocab/unit#desiredUnit>) }
BIND (geof:area (?feature, <http://qudt.org/vocab/unit#desiredUnit>) as ?area)

Hope this helps!

Cheers,
Stephen

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Samur Araujo

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Dec 14, 2016, 3:44:40 AM12/14/16

to sta...@clarkparsia.com, Gianluca Gindro, m.nel...@geophy.com

Hi Stephen, thank you a lot for the clarification.

This was really helpful and will save us a considerable amount of time.

Best regards,

Samur Araujo

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Geophy

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Samur Araujo

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Dec 14, 2016, 4:20:05 AM12/14/16

to sta...@clarkparsia.com, Gianluca Gindro, m.nel...@geophy.com

Dear Stephen, I think may worth mention in the documentation that some of these methods are asymmetric.

If I use

?b geof:nearby (?a 1 <http://qudt.org/vocab/unit#Kilometer>).

or invert ?b and ?a

?a geof:nearby (?b 1 <http://qudt.org/vocab/unit#Kilometer>).

I get totally different response time.

For example, the two queries below return the same results but have a very different response time.

-----------------------------------------------------------------------------------------

prefix gn: <http://sws.geonames.org/>

prefix geo: <http://www.opengis.net/ont/geosparql#>

prefix sf: <http://www.opengis.net/def/sf/>

prefix g: <http://geophy.com/>

prefix geof: <http://www.opengis.net/def/function/geosparql/>

select *

where {

<http://geophy.data/fm#10> geo:hasGeometry ?a .

?t geo:hasGeometry ?b .

?b geof:nearby (?a 1 <http://qudt.org/vocab/unit#Kilometer>).

}

-----------------------------------------------------------------------------------------

prefix gn: <http://sws.geonames.org/>

prefix geo: <http://www.opengis.net/ont/geosparql#>

prefix sf: <http://www.opengis.net/def/sf/>

prefix g: <http://geophy.com/>

prefix geof: <http://www.opengis.net/def/function/geosparql/>

select *

where {

<http://geophy.data/fm#10> geo:hasGeometry ?a .

?t geo:hasGeometry ?b .

?a geof:nearby (?b 1 <http://qudt.org/vocab/unit#Kilometer>).

}

Samur Araujo

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Dec 14, 2016, 4:55:25 AM12/14/16

to sta...@clarkparsia.com, Gianluca Gindro, m.nel...@geophy.com

Apparently when I use lat long instead of point the geof:nearby does not work.

prefix gn: <http://sws.geonames.org/>

prefix geo: <http://www.opengis.net/ont/geosparql#>

prefix sf: <http://www.opengis.net/def/sf/>

prefix g: <http://geophy.com/>

prefix geof: <http://www.opengis.net/def/function/geosparql/>

prefix wgs: <http://www.w3.org/2003/01/geo/wgs84_pos#>

select *

where {

<http://geophy.data/fm#10> wgs:lat ?lat .

<http://geophy.data/fm#10> wgs:long ?long .

?t geo:hasGeometry ?b .

?b geof:nearby ( ?lat ?lon 1 <http://qudt.org/vocab/unit#Kilometer>).

}

--------------------------------------------------------------------------------------

ERROR 2016-12-14 10:54:05,886 [Stardog.Executor-981] com.complexible.stardog.protocols.server.SPECServerFunction:query(536): There was an error executing query: prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>

prefix owl: <http://www.w3.org/2002/07/owl#>

prefix xsd: <http://www.w3.org/2001/XMLSchema#>

prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#>

prefix gn: <http://sws.geonames.org/>

prefix geo: <http://www.opengis.net/ont/geosparql#>

prefix sf: <http://www.opengis.net/def/sf/>

prefix g: <http://geophy.com/>

prefix geof: <http://www.opengis.net/def/function/geosparql/>

prefix wgs: <http://www.w3.org/2003/01/geo/wgs84_pos#>

select *

where {

<http://geophy.data/fm#10> wgs:lat ?lat .

<http://geophy.data/fm#10> wgs:long ?long .

?t geo:hasGeometry ?b .

?b geof:nearby ( ?lat ?lon 1 <http://qudt.org/vocab/unit#Kilometer>).

} limit 50 offset 0

org.openrdf.query.QueryEvaluationException: com.complexible.stardog.plan.eval.ExecutionException: Latitude must be a double value between -90 & 90

at com.complexible.stardog.query.DefaultQueryFactory$TupleQuery.execute(DefaultQueryFactory.java:179) ~[stardog-4.2.1.jar:?]

at com.complexible.stardog.query.DefaultQueryFactory$TupleQuery.execute(DefaultQueryFactory.java:162) ~[stardog-4.2.1.jar:?]

at com.complexible.stardog.protocols.server.SPECServerFunction.query(SPECServerFunction.java:512) ~[stardog-protocols-spec-server-4.2.1.jar:?]

at com.complexible.stardog.protocols.server.SPECServerFunction.handleMessage(SPECServerFunction.java:152) ~[stardog-protocols-spec-server-4.2.1.jar:?]

at com.complexible.stardog.protocols.http.annex.QueryPanelEndpoint.handleMessage(QueryPanelEndpoint.java:89) ~[stardog-webconsole-annex-4.2.1.jar:?]

at com.complexible.common.protocols.server.rpc.ServerHandler.lambda$handleMessage$1(ServerHandler.java:336) ~[stardog-protocols-api-server-4.2.1.jar:?]

at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_111]

at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_111]

at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [?:1.8.0_111]

at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [?:1.8.0_111]

at java.lang.Thread.run(Thread.java:745) [?:1.8.0_111]

Caused by: com.complexible.stardog.plan.eval.ExecutionException: Latitude must be a double value between -90 & 90

at com.complexible.stardog.plan.eval.QueryEngine.getExecutablePlan(QueryEngine.java:252) ~[stardog-4.2.1.jar:?]

at com.complexible.stardog.plan.eval.QueryEngine.executeSelect(QueryEngine.java:127) ~[stardog-4.2.1.jar:?]

at com.complexible.stardog.query.DefaultQueryFactory$TupleQuery.execute(DefaultQueryFactory.java:176) ~[stardog-4.2.1.jar:?]

... 10 more

Caused by: com.complexible.stardog.plan.PlanException: Latitude must be a double value between -90 & 90

at com.complexible.stardog.plan.parser.QueryParserImpl.parseQuery(QueryParserImpl.java:488) ~[stardog-4.2.1.jar:?]

at com.complexible.stardog.plan.PlanContext.planFor(PlanContext.java:87) ~[stardog-4.2.1.jar:?]

at com.complexible.stardog.plan.eval.QueryEngine.getExecutablePlan(QueryEngine.java:229) ~[stardog-4.2.1.jar:?]

at com.complexible.stardog.plan.eval.QueryEngine.executeSelect(QueryEngine.java:127) ~[stardog-4.2.1.jar:?]

at com.complexible.stardog.query.DefaultQueryFactory$TupleQuery.execute(DefaultQueryFactory.java:176) ~[stardog-4.2.1.jar:?]

... 10 more

Caused by: java.lang.IllegalStateException: Latitude must be a double value between -90 & 90

at com.complexible.stardog.spatial.db.query.NearbyPropertyFunction$NearbyPlanNodeBuilder.validate(NearbyPropertyFunction.java:197) ~[stardog-spatial-core-4.2.1.jar:?]

at com.complexible.stardog.plan.AbstractPlanNodeBuilder.build(AbstractPlanNodeBuilder.java:85) ~[stardog-4.2.1.jar:?]

at com.complexible.stardog.plan.AbstractPropertyFunctionNodeBuilder.build(AbstractPropertyFunctionNodeBuilder.java:20) ~[stardog-4.2.1.jar:?]

at com.complexible.stardog.plan.PropertyFunctions$PropertyFunctionReplacer.transform(PropertyFunctions.java:293) ~[stardog-4.2.1.jar:?]

at com.complexible.stardog.plan.TransformingPlanNodeVisitor.visit(TransformingPlanNodeVisitor.java:711) ~[stardog-4.2.1.jar:?]

at com.complexible.stardog.plan.ScopeNodeImpl.accept(ScopeNodeImpl.java:122) ~[stardog-4.2.1.jar:?]

at com.complexible.stardog.plan.TransformingPlanNodeVisitor.unaryVisit(TransformingPlanNodeVisitor.java:549) ~[stardog-4.2.1.jar:?]

at com.complexible.stardog.plan.TransformingPlanNodeVisitor.unaryTransform(TransformingPlanNodeVisitor.java:79) ~[stardog-4.2.1.jar:?]

at com.complexible.stardog.plan.TransformingPlanNodeVisitor.transform(TransformingPlanNodeVisitor.java:306) ~[stardog-4.2.1.jar:?]

at com.complexible.stardog.plan.TransformingPlanNodeVisitor.visit(TransformingPlanNodeVisitor.java:767) ~[stardog-4.2.1.jar:?]

at com.complexible.stardog.plan.ProjectionPlanNodeImpl.accept(ProjectionPlanNodeImpl.java:104) ~[stardog-4.2.1.jar:?]

at com.complexible.stardog.plan.TransformingPlanNodeVisitor.unaryVisit(TransformingPlanNodeVisitor.java:549) ~[stardog-4.2.1.jar:?]

at com.complexible.stardog.plan.TransformingPlanNodeVisitor.unaryTransform(TransformingPlanNodeVisitor.java:79) ~[stardog-4.2.1.jar:?]

at com.complexible.stardog.plan.TransformingPlanNodeVisitor.transform(TransformingPlanNodeVisitor.java:316) ~[stardog-4.2.1.jar:?]

at com.complexible.stardog.plan.TransformingPlanNodeVisitor.visit(TransformingPlanNodeVisitor.java:759) ~[stardog-4.2.1.jar:?]

at com.complexible.stardog.plan.SlicePlanNodeImpl.accept(SlicePlanNodeImpl.java:103) ~[stardog-4.2.1.jar:?]

at com.complexible.stardog.plan.PropertyFunctions.apply(PropertyFunctions.java:171) ~[stardog-4.2.1.jar:?]

at com.complexible.stardog.plan.parser.QueryParserImpl.postProcess(QueryParserImpl.java:519) ~[stardog-4.2.1.jar:?]

at com.complexible.stardog.plan.parser.QueryParserImpl.parseQuery(QueryParserImpl.java:463) ~[stardog-4.2.1.jar:?]

at com.complexible.stardog.plan.PlanContext.planFor(PlanContext.java:87) ~[stardog-4.2.1.jar:?]

at com.complexible.stardog.plan.eval.QueryEngine.getExecutablePlan(QueryEngine.java:229) ~[stardog-4.2.1.jar:?]

at com.complexible.stardog.plan.eval.QueryEngine.executeSelect(QueryEngine.java:127) ~[stardog-4.2.1.jar:?]

at com.complexible.stardog.query.DefaultQueryFactory$TupleQuery.execute(DefaultQueryFactory.java:176) ~[stardog-4.2.1.jar:?]

... 10 more

ERROR 2016-12-14 10:54:05,887 [Stardog.Executor-981] com.complexible.common.protocols.server.rpc.ServerHandler:exceptionCaught(413): exceptionCaughtServerHandler