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Comment by scdoshi | Hacker News Reader

S2, linked from the README[1], does the same hierarchical subdivisions in squares, with each square having a string ID.

Squares divide into sub-squares exactly, but hexagon's don't sub-divide into hexagon's neatly.[2]

Can someone explain the advantages of hexagons over squares in this use case?

[1]https://code.google.com/archive/p/s2-geometry-library/ [2]https://www.illustrativemathematics.org/content-standards/ta...

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Gosper island shapes do subdivide into gosper island shapes, if you want something tricky: https://en.wikipedia.org/wiki/Gosper_curve#Properties

See sibling post for links, but the short answer: you can use 12 pentagons, strategically interspersed. Like a (soccer) football.

edit: Oops, that only explains the tiling. For explanations of how the hierarchy descends, Dr. Sahr produced some GIFs that give a little bit of an overview of how the resolutions overlay: http://webpages.sou.edu/~sahrk/dgg/images/topogif/topogif.ht...

Thanks for that link.

Also found this which goes into some more detailed comparison with rectangular grids:

https://github.com/uber/h3/blob/master/docs/doxyfiles/usecas...

Boundaries between all 6 neighbors are equal. With S2, four are on the sides and top are equal and the corner neighbors have only a single point as their boundary.

This means you can better simulate dynamic systems where there is flow between cells.

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