mortie 0.0.0

Morton numbering and indexing for healpix grids

mortie

Mortie is a library for applying morton indexing to healpix grids. Morton numbering (also called z-ordering) facilitates several geospatial operators such as buffering and neighborhood look-ups, and can generally be thought of as a type of geohashing.

This particular implementation focuses on hierarchical healpix maps, and is mostly inspired from this paper.

TODO:

• add paper reference
• add funding information
• add tests
• remove / prune dead code
• add example(s)
• fix north / south bug
• remove numba dependency
• update documentation
• publish to pypi

Dependencies currently are numpy, numba, and healpy. Ideally, this will be reduced to just healpy and numpy in the near future. Although not a dependency, there are several functions that have been written to interface with the vaex project. The environment.yaml file contains a full plotting environment needed to run the examples; setup.py will only build the minimum requirements for only the library.

Funding

Initial funding of this work was supported by the ICESat-2 project science office, at the Laboratory for Cryospheric Sciences (NASA Goddard, Section 615).

References

[1] Youngren, Robert W., and Mikel D. Petty. "A multi-resolution HEALPix data structure for spherically mapped point data." Heliyon 3.6 (2017): e00332. doi: 10.1016/j.heliyon.2017.e00332