5 unstable releases
0.3.2 | Oct 12, 2024 |
---|---|
0.3.1 | May 1, 2023 |
0.3.0 | Apr 28, 2023 |
0.2.0 | Jan 29, 2023 |
0.1.0 | Sep 21, 2022 |
#461 in Data structures
99KB
2K
SLoC
HexTree
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
.
How is this different from HashMap<H3Cell, V>
?
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.
Features
serde
: support for serialization via serde.
License
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.
Contribution
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.
Dependencies
~0–375KB