README
This README is the one indexed from the repository at its latest ref, not from the tag for this version.
Crystal Lang S2 Cells
Maps Lat Lon coordinates to S2 Cells. Useful for things like storing points in InfluxDB
Installation
-
Add the dependency to your
shard.yml:dependencies: s2_cells: github: spider-gazelle/s2_cells -
Run
shards install
Usage
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))