Re^3: Lookup closest hash key

[bart]

The OP is only interested in nearest in a one-dimensional space.

Actually, I don't think he is. This looks like an XY problem to me, and I think Corion thought the same thing...

Distances between cities is intrinsically a 2-dimensional problem.

We don't know what the rest of the OP's code does, but I assume it's something that could be better integrated with a solution to the question that was asked.

[LanX]

> Distances between cities is intrinsically a 2-dimensional problem.

My understanding was that the distances are calculated starting from a 0km origin, hence it's one dimensional.

And I'm not sure if Corion's suggestions can be easily applied to spherical distances...

[JavaFan]

Actually, I don't think he is.

Considering the OP actually gave us an example hash, and an example search query, I'm not going to assume he has figured out how to use spherical coordinates as hash keys. (For which neither Voronoi diagrams, nor quadtrees can be used directly).