A list of SPARQL ready-to-be-pasted binding blocks to compute operations on (lat,lon) pairs
Let's assume you are on a boat and have to navigate only basic items such as a map or a compass, and a . . . . . . SPARQL engine! How to set a course? How to compute distances? Here, we provide a set of SPARQL code-blocks to be used in such situation and more generally in use-cases where practitioners need to compute mathematical calculus on geo-data represented by (lat,lon) pairs.
The repository provides several ready-to-be-used bindings blocks of SPARQL 1.1. Practically, the various funtions are split in several files which are all self-contained. They are all adopting the same structure.
Warning: If a specific requires to use several blocks within the same final SPARQL query, the query designer will have to pay attention to the multiple intermediate variables (e.g. ?sub1, ?sub2, ...) to be sure that the same (sub-)variable will not be called by different feature-blocks, otherwise renaming actions should be taken!
This repository contains:
README.md(this file): providing documentation;distance_great_circle.txt: taking two (lat,lon) points, returns their great-circle distance on Earth;distance_equirectangular_approx.txt: performs an equirectangular approximation to compute the distance between points;distance_to_horizon.txt: returns the distance to the horizon from a specific height;initial_bearing_great_circle.txt: gives the initial bearing for a great-circle course between two points;mid_point_great_circle.txt: computes the coordinates (lat,lon) in radians of the mid-point of a great-circle course between two points (considering their lat/lon coordinates in degrees);LICENSE.
Damien Graux https://dgraux.github.io/
Inria, France
2022