# Polars H3

> Polars-native H3 expressions for indexing, inspection, hierarchy, traversal, directed edges, vertices, metrics, and optional Folium graphing.

Polars H3 functions accept Polars column names or expressions and return `pl.Expr`. H3 indexes are supported as unsigned 64-bit integers, signed 64-bit integers, or hexadecimal strings where documented. Unsigned 64-bit integers are preferred for computation. H3 resolutions range from 0 through 15. Polygon-to-cells and cells-to-polygon geometry conversion are outside this package's scope.

## Start here

- [Getting started](https://raw.githubusercontent.com/Filimoa/polars-h3/master/docs/getting-started.md): Installation, a complete coordinate-to-cell example, and lazy expression composition.
- [User guide](https://raw.githubusercontent.com/Filimoa/polars-h3/master/docs/guide.md): Index representations, function families, resolutions, and list-valued results.

## API reference

- [API overview](https://raw.githubusercontent.com/Filimoa/polars-h3/master/docs/api-reference/index.md): Map of the public function families.
- [Indexing](https://raw.githubusercontent.com/Filimoa/polars-h3/master/docs/api-reference/indexing.md): Coordinate, cell center, local IJ, and boundary expressions.
- [Index inspection](https://raw.githubusercontent.com/Filimoa/polars-h3/master/docs/api-reference/inspection.md): Validation, representation conversion, and index metadata.
- [Hierarchy](https://raw.githubusercontent.com/Filimoa/polars-h3/master/docs/api-reference/hierarchy.md): Parent/child traversal, compacting, and uncompacting.
- [Directed edges](https://raw.githubusercontent.com/Filimoa/polars-h3/master/docs/api-reference/edge.md): Neighbor checks and directed-edge construction and inspection.
- [Traversal](https://raw.githubusercontent.com/Filimoa/polars-h3/master/docs/api-reference/traversal.md): Grid distance, rings, disks, and paths.
- [Vertices](https://raw.githubusercontent.com/Filimoa/polars-h3/master/docs/api-reference/vertexes.md): Cell vertices, vertex validation, and coordinates.
- [Metrics](https://raw.githubusercontent.com/Filimoa/polars-h3/master/docs/api-reference/metrics.md): Great-circle distance, areas, edge lengths, cell counts, and pentagons.
- [Graphing](https://raw.githubusercontent.com/Filimoa/polars-h3/master/docs/graphing.md): Optional Folium visualization helpers.

## Source and tests

- [Public Python API](https://raw.githubusercontent.com/Filimoa/polars-h3/master/polars_h3/__init__.py): Canonical public exports.
- [Python wrapper source](https://github.com/Filimoa/polars-h3/tree/master/polars_h3/core): Signatures and implementation-facing docstrings.
- [Test suite](https://github.com/Filimoa/polars-h3/tree/master/tests): Executable behavior and dtype coverage.
