Show HN: ProximityHash – Geohashes in Proximity

Re:Show HN: ProximityHash – Geohashes in Proximity by goodells on Wednesday June 07, 2017 @04:33PM (#14509642)

I'm a bit confused about the "hash" part of this... wouldn't you want to be able to go back from the hashed string to the original location? I can't think of much of a use for only being able to test locations to see if they match a proximity hash.

Internally, the space-filling curves are super interesting. I highly recommend this writeup [1] on how they're used in things like planet-sized maps. I've heard rumors that Google adjusts the offset of their space-filling curves to minimize large discontinuities near land and push them over the ocean instead.

[1] - http://blog.notdot.net/2009/11/Damn-Cool-Algorithms-Spatial-...

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Re:Show HN: ProximityHash – Geohashes in Proximity by ashwinnair on Friday June 09, 2017 @08:01AM (#14520777)

You can decode the hash back to the location coordinate. In fact if you look at the code, you'll see that the output is a set of points which are then geohash encoded in order to get the hashed value.

Would surely go through the blog mentioned. Thanks.

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