Use Case ONTO22: Shortest Line

[ar-chad]

Use Case ONTO22

Shortest Line

As a GeoSPARQL data user I would like to retrieve the shortest line corresponding to minimum distance between two geometries - distance between their closest points.

Distance is measured in the units of the spatial reference system.

For the POINT(4 3 0) and the LINESTRING(0 0 0, 4 2 0) the value is LINESTRING (4 3 0, 4 2 0).

Function signature:

shortestLine(geometry: ogc:geomLiteral, geometry: ogc:geomLiteral): geometry: ogc:geomLiteral

Actor: GeoSPARQL data user (human or software agent querying RDF dataset with GeoSPARQL)

Preconditions

Features and Geometries with 2D and 3D representations are present in a dataset to be queried. The shortest line function is discoverable.

Postconditions

A SPARQL query can be executed that includes a function to return shortest line from a given geometry to another given geometry - corresponding to the distance between their closest points. The results of the query are known to be true or false in 2D and 3D.

Steps

Actor: discovers shortest line function implemented by the system
Actor: executes a SPARQL query containing shortest line function with two geometries as arguments.
System: returns a SPARQL result with a shortest line between geometries - corresponding to distance between their closest points.