https://github.com/spider-gazelle/s2_cells

maps latitude and longitude to S2 Cells https://s2geometry.io/
https://github.com/spider-gazelle/s2_cells

Last synced: 3 months ago
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maps latitude and longitude to S2 Cells https://s2geometry.io/

• Host: GitHub
• URL: https://github.com/spider-gazelle/s2_cells
• Owner: spider-gazelle
• License: mit
• Created: 2020-10-08T14:57:05.000Z (about 4 years ago)
• Default Branch: master
• Last Pushed: 2024-07-27T14:10:12.000Z (3 months ago)
• Last Synced: 2024-07-28T14:29:51.250Z (3 months ago)
• Language: Crystal
• Size: 47.9 KB
• Stars: 0
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

• awesome-crystal - s2_cells - [S2 Geometry](https://s2geometry.io/devguide/s2cell_hierarchy.html) for spatial indexing (Algorithms and Data structures)

README

        
# Crystal Lang S2 Cells

[![CI](https://github.com/spider-gazelle/s2_cells/actions/workflows/ci.yml/badge.svg)](https://github.com/spider-gazelle/s2_cells/actions/workflows/ci.yml)

Maps Lat Lon coordinates to S2 Cells.

Useful for things like storing points [in InfluxDB](https://docs.influxdata.com/influxdb/v2.0/reference/flux/stdlib/experimental/geo/#geo-schema-requirements)

## Installation

1. Add the dependency to your `shard.yml`:

   ```yaml

   dependencies:

     s2_cells:

       github: spider-gazelle/s2_cells

   ```

2. Run `shards install`

## Usage

```crystal

require "s2_cells"

# index a location in your database

lat = -33.870456

lon = 151.208889

level = 24

cell = S2Cells.at(lat, lon).parent(level)

token = cell.to_token # => "3ba32f81"

# or

id = cell.id # => Int64

# find all the indexes in an area

p1 = S2Cells::LatLng.from_degrees(33.0, -122.0)

p2 = S2Cells::LatLng.from_degrees(33.1, -122.1)

cells = S2Cells.in(p1, p2) # => Array(CellId)

# then can search your index:

# loc_index = ANY(cells.map(&.id))

```

## Reference

a crystal clone of https://github.com/sidewalklabs/s2sphere