Tuesday 16 May 2017

How to calculate the neighbouring grids on geohash. Algorithms required

Hi I am working with a database with an implementation of geohash

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So as shown above, as the zoom level goes down (6 zoom levels), more of abcd gets inserted into each grid. I have represented them as a rigid grid; however, the central point is different for all the grids. So for example, distance from a to b will not be the same as distance from a to c.

If it was a rigid grid, I can just get the closest four neighbouring grids; however, I cannot do that as the distances vary and the closest neighbours are not necessarily orthogonal. Only information that I have from the database is the centra point of each grid and the geohash key e.g. aa, ab, etc..

How will I find girds that are just north, west, east and south of each grid for every zoom level? (have 6 zoom levels)



via serendipity

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