# SpatialHash
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A library for calculating spatial hashes for points and geometries.
This is most useful for building spatial databases with very fast indexing.
## Installation
```elixir
defp deps do
[{:spatial_hash, "~> 0.1.0"}]
end
```
## Usage
**[Full Documentation](https://hexdocs.pm/spatial_hash/SpatialHash.html)**
The `SpatialHash` module provides a `hash` function that takes a single point on any dimension
as an array of coordinates and an array of gridding properties for each dimension. Grid
properties are specified as a tuple of coordinate min and max as well as a step value for
the grid spacing. Convenience function of `SpatialHash.world_grid()` is provided that
returns a grid of the entire world in degress with step value roughly equivalent to 10 meters.
A `hash_range` function is also provided that takes an Envelope or Geometry and returns
the range covered in each dimension.
```elixir
SpatialHash.hash_range(
%Envelope{
min_x: -90.082756,
min_y: 29.949766,
max_x: -90.079484,
max_y: 29.952280
}, [{-180, 180, 0.01}, {-90, 90, 0.01}]) // -> [8991..8992, 11994..11995]
SpatialHash.hash_range(
%{type: "LineString", coordinates: [
{ -90.082746, 29.950955},
{-90.081453, 29.952280},
{-90.079489, 29.949770}
]}, SpatialHash.world_grid) // -> [89917..89920, 119949..119952]
```