mortie

Documentation Tests Docs CodSpeed codecov PyPI version Python 3.10+ CodSpeed Badge Binder

Morty using 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.

Documentation

The full documentation — the generated API reference alongside the specification, interchange and coverage guides — is published at espg.github.io/mortie. Every page below is rendered there; the in-tree markdown links are the same content at the revision you are reading.

The normative encoding and conventions — the packed-word bit layout, the decimal string grammar, the order 0–29 resolution table, the morton-hive store layout, and the coverage-MOC serializations, all frozen for the 1.x series — are documented in docs/specification.md. Moving a packed word to and from the wider HEALPix ecosystem (cdshealpix / healpy (order, nested-pixel) pairs) is covered in docs/healpix_interchange.md.

Performance

Mortie's morton core is a Rust extension and the sole runtime path — there is no Python implementation to fall back on — so performance is reported as absolute throughput rather than a speedup ratio. Encoding (geo2mort) and decoding (mort2geo) run at tens of millions of morton indices per second on one core, staying within roughly 2× across orders 4–29.

See docs/benchmarks.md for the full cross-order table (raw encode / decode throughput and coverage timing at orders 4 / 12 / 18 / 29), regenerated in place by a committed script. Cell counts there are deterministic; timings are machine/run dependent.

Pre-built wheels are available for Linux, macOS, and Windows. The Rust extension is required and is included in all pip-installed wheels.

Installation

pip install mortie

For development builds with Rust, see BUILDING.md.

Spatial Buffer

Mortie provides a morton_buffer function for expanding a set of morton cells by a configurable border ring. This is useful for... well, buffering.

import numpy as np
import mortie

# Convert coordinates to morton cells at order 6
cells = np.unique(mortie.geo2mort(lats, lons, order=6))

# Expand by 1-cell ring (8-connected neighbors)
border = mortie.morton_buffer(cells, k=1)
expanded = np.union1d(cells, border)

Latitude convention. Since 0.10 geo2mort and the coverage kernels take WGS84 geodetic latitude and map it to the authalic sphere, so cells are equal-area on the ellipsoid. Cell ids therefore differ from pre-0.10 mortie and from raw-spherical HEALPix libraries; pass latitude="geodetic-spherical" for the old behaviour. See docs/specification.md §9.

All input indices must be at the same order. The function returns only the new border cells, not the input cells themselves.

Polygon Coverage

morton_coverage computes the set of morton indices that cover a polygon defined by lat/lon vertices. It uses a top-down hierarchical descent over the HEALPix tree: starting from the 12 base cells it keeps cells inside the polygon, prunes cells outside, and refines cells the boundary passes through down to the requested order. Cost scales with the polygon's boundary, not its area — interior regions collapse to a few coarse cells, so a large but simple polygon is cheap. Vertex count still matters (a one-time O(V) edge/seed setup, plus per-boundary-cell work that grows with local edge density), but far more gently than the old O(cells × vertices) approach — a 1M-vertex polygon covers in ~1 s, roughly 40× faster than before.

import mortie

# Define polygon vertices (lat, lon in degrees)
lats = [40.0, 40.0, 50.0, 50.0]
lons = [-125.0, -115.0, -115.0, -125.0]

# Flat cover — every cell at order 6
cells = mortie.morton_coverage(lats, lons, order=6)

# Compact Multi-Order Coverage — coarse interior, fine boundary (usually far smaller)
moc = mortie.morton_coverage_moc(lats, lons, order=10)

# Adaptive boundary: stop at an angular tolerance, or cap the cell count
moc_tol = mortie.morton_coverage_moc(lats, lons, order=10, tolerance=0.5)   # degrees
moc_bud = mortie.morton_coverage_moc(lats, lons, order=10, max_cells=500)

The function handles concave polygons, antimeridian-crossing polygons, and polar regions. Multipart polygons and holes are supported by passing a list of rings (even-odd fill): disjoint parts are unioned and a nested ring carves a hole, so a donut is [outer, hole]. Helpers compress_moc (merge 4-sibling groups) and moc_to_order (densify a MOC to a flat order) round out the API. See docs/coverage_methods.md for the full method/precision/runtime trade-offs and a benchmark matrix.

Dependencies

numpy. All HEALPix operations use the Rust-native healpix crate bundled in the compiled extension — no external HEALPix library is needed.

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

Project links

Data verified by PyPI on Aug 16, 2026
Data provided by the project maintainers, verified at the time the release was uploaded to PyPI.

Key dates

PyPI data
Data sourced directly from PyPI's database.
  • Released:
Newer release available (0.9.11)

1 maintainer

PyPI data
Data sourced directly from PyPI's database.
Avatar for espg from gravatar.com espg

Credits

Author: Shane Grigsby (espg)

GitHub Statistics

Data verified by PyPI on Aug 16, 2026
The GitHub source repository was provided by the project maintainers and verified by PyPI at the time of upload. Stars, forks, and open issues/PRs are derived from that repository and have not been independently verified.

License

MIT License

Requires

Python >=3.10

Provides Extra

arro3 bench examples pandas pyarrow test

Tags

healpix geohashing morton index

Classifiers

Report project as malware

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

mortie-0.9.8.tar.gz (17.1 MB view details)

Uploaded Source

Built Distributions

If you're not sure about the file name format, learn more about wheel file names.

mortie-0.9.8-cp310-abi3-win_amd64.whl (14.9 MB view details)

Uploaded CPython 3.10+Windows x86-64

mortie-0.9.8-cp310-abi3-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (14.9 MB view details)

Uploaded CPython 3.10+manylinux: glibc 2.17+ x86-64

mortie-0.9.8-cp310-abi3-manylinux_2_17_aarch64.manylinux2014_aarch64.whl (14.8 MB view details)

Uploaded CPython 3.10+manylinux: glibc 2.17+ ARM64

mortie-0.9.8-cp310-abi3-macosx_11_0_arm64.whl (14.8 MB view details)

Uploaded CPython 3.10+macOS 11.0+ ARM64

mortie-0.9.8-cp310-abi3-macosx_10_12_x86_64.whl (14.8 MB view details)

Uploaded CPython 3.10+macOS 10.12+ x86-64

File details

Details for the file mortie-0.9.8.tar.gz.

File metadata

  • Download URL: mortie-0.9.8.tar.gz
  • Upload date:
  • Size: 17.1 MB
  • Tags: Source
  • Uploaded using Trusted Publishing? Yes
  • Uploaded via: twine/7.0.0 CPython/3.13.14

File hashes

Hashes for mortie-0.9.8.tar.gz
Algorithm Hash digest
SHA256 cf1e291d2ade8fe4cf5f25231cbb333f038cb66f176e8454de095e16cd201b6b
MD5 93b6c258d3dbbb84e79038774b51e204
BLAKE2b-256 3211d18dc691add403726aa1ca06bdc4e0f320e20a64b0a40c1d966b32e745ea

See more details on using hashes here.

Provenance

The following attestation bundles were made for mortie-0.9.8.tar.gz:

Publisher: build-wheels.yml on espg/mortie

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

File details

Details for the file mortie-0.9.8-cp310-abi3-win_amd64.whl.

File metadata

  • Download URL: mortie-0.9.8-cp310-abi3-win_amd64.whl
  • Upload date:
  • Size: 14.9 MB
  • Tags: CPython 3.10+, Windows x86-64
  • Uploaded using Trusted Publishing? Yes
  • Uploaded via: twine/7.0.0 CPython/3.13.14

File hashes

Hashes for mortie-0.9.8-cp310-abi3-win_amd64.whl
Algorithm Hash digest
SHA256 0a95ee527ad12d2a987078f7d53bc75b37c7e5fa7243c43428ef87ac33e499b4
MD5 ca3ce34656d50d43f291af745af6424d
BLAKE2b-256 0af078e59dab02dd768a99021d1ab18cf7c1473fe68b274e2941d07f92f1dca3

See more details on using hashes here.

Provenance

The following attestation bundles were made for mortie-0.9.8-cp310-abi3-win_amd64.whl:

Publisher: build-wheels.yml on espg/mortie

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

File details

Details for the file mortie-0.9.8-cp310-abi3-manylinux_2_17_x86_64.manylinux2014_x86_64.whl.

File metadata

File hashes

Hashes for mortie-0.9.8-cp310-abi3-manylinux_2_17_x86_64.manylinux2014_x86_64.whl
Algorithm Hash digest
SHA256 d4a42deff8028de2846b0980fb4aa87846d32f89c09ea8dc80f77991c028d028
MD5 2f94fa4322f7bff3aaffe7e2b4ec6de8
BLAKE2b-256 92b13251d4041df04bf5bf48e05b65bd0506dbd9b696c172d4e7d8726d5fd3a7

See more details on using hashes here.

Provenance

The following attestation bundles were made for mortie-0.9.8-cp310-abi3-manylinux_2_17_x86_64.manylinux2014_x86_64.whl:

Publisher: build-wheels.yml on espg/mortie

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

File details

Details for the file mortie-0.9.8-cp310-abi3-manylinux_2_17_aarch64.manylinux2014_aarch64.whl.

File metadata

File hashes

Hashes for mortie-0.9.8-cp310-abi3-manylinux_2_17_aarch64.manylinux2014_aarch64.whl
Algorithm Hash digest
SHA256 15bfb4df43c9c404cb180c208a76b91c534bc0b0eb6c063171245b59898cbc4f
MD5 8d32d2bb7d7e73fc09abc1433a3f0d2b
BLAKE2b-256 9dfeb5e363afe81696b4164420734f77f403546e35ea0f850d8522a2310bac52

See more details on using hashes here.

Provenance

The following attestation bundles were made for mortie-0.9.8-cp310-abi3-manylinux_2_17_aarch64.manylinux2014_aarch64.whl:

Publisher: build-wheels.yml on espg/mortie

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

File details

Details for the file mortie-0.9.8-cp310-abi3-macosx_11_0_arm64.whl.

File metadata

File hashes

Hashes for mortie-0.9.8-cp310-abi3-macosx_11_0_arm64.whl
Algorithm Hash digest
SHA256 989b51ee29a78dfc4e8ebcb432553872937d6129faaabac4768044134abb98c4
MD5 2c05dc11b8c952882e028cb938ca91e5
BLAKE2b-256 a477023c310a8aa9fff8d88135c94643c93cdb5aae73e0f25ba8b71a6b7717a1

See more details on using hashes here.

Provenance

The following attestation bundles were made for mortie-0.9.8-cp310-abi3-macosx_11_0_arm64.whl:

Publisher: build-wheels.yml on espg/mortie

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

File details

Details for the file mortie-0.9.8-cp310-abi3-macosx_10_12_x86_64.whl.

File metadata

File hashes

Hashes for mortie-0.9.8-cp310-abi3-macosx_10_12_x86_64.whl
Algorithm Hash digest
SHA256 a51584ebb954901fd887697fb641a2449f0aa6a3a2b1a9a2770c74347593bc2c
MD5 209f4f1e61658d75945f034591904c6b
BLAKE2b-256 3dcee163ee4857b942d2b39a7bdd0fc93b1c5d06a1c44bd7e5094a567fb7aa74

See more details on using hashes here.

Provenance

The following attestation bundles were made for mortie-0.9.8-cp310-abi3-macosx_10_12_x86_64.whl:

Publisher: build-wheels.yml on espg/mortie

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

Release history Release notifications | RSS feed

0.9.11

6 files

0.9.10

6 files

0.9.9

6 files

This release

0.9.8 This release

6 files

0.9.7

6 files

0.9.6

6 files

0.9.5

6 files

0.9.4

6 files

0.9.3

6 files

0.9.2

6 files

0.9.1

6 files

0.9.0

6 files

0.8.5

6 files

0.8.4

6 files

0.8.3

6 files

0.8.2

6 files

0.8.1

6 files

0.8.0

6 files

0.7.2

6 files

0.7.1

6 files

0.7.0

6 files

0.6.6

6 files

0.6.5

6 files

0.6.4

6 files

0.6.3

6 files

0.6.2

6 files

0.6.1

6 files

0.5.2

6 files

0.5.1

5 files

0.5.0

5 files

0.4.10

5 files

0.4.8

5 files

0.4.7

5 files

0.4.6

5 files

0.4.5

5 files

0.4.4

5 files

0.4.3

5 files

0.4.0

5 files

0.3.1

2 files

0.2.0

2 files

0.1.0

1 file

0.0.0

2 files

Supported by

AWS Cloud computing and Security Sponsor Datadog Monitoring Depot Continuous Integration Fastly CDN Google Download Analytics Sentry Error logging StatusPage Status page