Which are great right up until you cross boundaries. IIRC there's a big boundary in Google's S2 that divides Toronto in half.
Re:Why Bother with What Three Words?
by thanatropism on Thursday March 28, 2019 @11:34PM
(#19518954)
That’s also a problem when mapping a circle to a straight line. The band Rush sang “you can’t have something for nothing...”
Geohashes are really cool, glad to see them mentioned in this thread. If you aren't familiar, you owe it to yourself to read the second Wikipedia article linked by the parent, it's a neat concept.
Yep. I saw a talk a while back about Uber sharding their caching layer by geohash
See also this http://www.drdobbs.com/database/space-filling-curves-in-geos... (Dr.Dobbs Journal, 1999).
It explains how to easily search for "points no more than X km from Y" in a DB query without having to actually calculate distances.
Re:Why Bother with What Three Words?
by thanatropism on Friday March 29, 2019 @02:33PM
(#19524292)
I wonder if space filling curves are used in the Python GIS stack for radius queries.
https://en.wikipedia.org/wiki/Z-order_curve
With that you can have a linear ordering of space at each scale. Rounding errors become rounding errors. I remember seeing an implementation of that on npm or some such thing.
https://en.wikipedia.org/wiki/Geohash