While this won't help you for data from the SPARQL endpoint, the Geo library can be of use when

working with coordinates from Wikidata/Wikibase.

This library is used by Wikibase and can thus both parse the coordinates coming from the wiki software

and format coordinates to a format the wiki software supports. This library is also used by

Semantic MediaWiki [0] and the Maps extension [1], so aids interoperability there as well.

[0] https://www.semantic-mediawiki.org

[1] https://github.com/JeroenDeDauw/Maps#maps

Cheers

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Jeroen De Dauw | www.EntropyWins.wtf | www.Professional.Wiki