i’m looking at the possibility of setting up an RDF source for data that is not easy to represent in the OSM data schema, stuff that we can synthesize easily in, say, leaflet or maplibre widgets or other visualization tools. anyone have any experience with this? i have a linode linux instance where i can play, and i see something from apache that might serve if i can use it with nginx.
comments or suggestions?
Can you elaborate on what the RDF source would contain? Would this be straight-up OHM data or something to supplement it?
this would be supplemental material, which is not reasonable to represent in OHM. for example, in my Antietam battlefield map, i have geographical information mostly on where regiments were located on the battlefield at various points in time. the regiments are components of brigades, which are then components of divisions, which are then components of corps, and so forth. these could be cobbed together using relations, but that model has a lot of problems (i played with it and i don’t like how it was working out.) so the OOB for the two armies on a battlefield is something better retreived from a non geographical source.
Is it anything that can be modeled in Wikidata? Then you can query Wikidata using the Wikidata Query Service, or you can join Wikidata and OHM using QLever. Both services are RDF-based; there are alternative tools if you really need raw RDF.
quite possibly. but i don’t have a good read on what kind of information density they want to have in wikidata. OOB data (sticking with my example) evolves as units are assigned/reassigned and commanders change. it’s temporarily dense like everything else we are interested in.
Wikidata does accept time-qualified data up to a certain point. But community members start to get a bit anxious when they have to scroll past pages and pages of statements about the same property on a given item. That was the original catalyst for chronology relations in OHM. If you just need a place to store a table of time series data, Wikimedia Commons accepts JSON files (“tabular data”), which other wikis can query somewhat manually, but there’s currently no support for big-data querying in RDF.
my concern about whether wikidata would find this acceptable is why i want to understand various RDF/SPARQL options.
The nice thing about Wikidata is that units and commanders are definitely within the project’s scope, and many have probably already been added to the database. If you find the Wikibase data model to be useful but don’t find it important to leverage those connections, it would be possible to set up a separate Wikibase instance somewhere, potentially hosted by Wikibase Cloud.
i’ll look at what’s out there already and see what level of detail is present. when mapping cavalry campaigns, it’s not uncommon to have different troops out on different roads, which is a pretty low level unit.
what i see there could constitute a start. i’d be aiming for data that’s more complete and organized and may well be in excess of what would be wanted by the existing wikidata community. once i have some proof of concept, i may want some guidance on setting up my own instance.
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