hextree provides tree structures that represent geographic regions with H3 cells.
The primary structures are:
- HexTreeMap: an H3 cell-to-value map.
- HexTreeSet: an H3 cell set for hit-testing.
You can think of HexTreeMap vs. HexTreeSet as HashMap vs. HashSet.
The key feature of a hextree is that its keys (H3 cells) are
hierarchical. For instance, if you previously inserted an entry for a
low-res cell, but later query for a higher-res child cell, the tree
returns the value for the lower res cell. Additionally, with
compaction, trees can automatically coalesce adjacent high-res cells
into their parent cell. For very large regions, the compaction process
can continue to lowest resolution cells (res-0), possibly removing
millions of redundant cells from the tree. For example, a set of
4,795,661 res-7 cells representing North America coalesces into a
42,383 element HexTreeSet.
A hextree's internal structure exactly matches the semantics of an H3 cell. The root of the tree has 122 resolution-0 nodes, followed by 15 levels of 7-ary nodes. The level of an occupied node, or leaf node, is the same as its corresponding H3 cell resolution.
serde: support for serialization via serde.
Licensed under either of
- Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
- MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)
at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.