clojure-polyline

Decoding and encoding of the google polyline algorithm as described at https://developers.google.com/maps/documentation/utilities/polylinealgorithm

Releases

Current stable release is 0.3.0, which requires Clojure 1.7 or later.

Leiningen dependency information:

[com.michaelgaare/clojure-polyline "0.3.0"]

Usage

(require '[com.michaelgaare.clojure-polyline :as polyline])

;; Decode a polyline string:
(polyline/decode "_p~iF~ps|U_ulLnnqC_mqNvxq`@")
;; => ({:longitude -120.2, :latitude 38.5} {:longitude -120.95, :latitude 40.7} {:longitude -126.453, :latitude 43.252})

;; Encode a collection of coordinates:
(polyline/encode [[38.5 -120.2] [40.7 -120.95] [43.252 -126.453]])
;; => "_p~iF~ps|U_ulLnnqC_mqNvxq`@"

encode expects a sequence of vectors of the format [latitude longitude] - if you have this as a sequence of maps of the format {:longitude longitude :latitude latitude} you can use coords->vec to convert to a collectoin of coordinate vectors.

You can use also use to-coords to turn a collection of [latitude longitude] vectors into the map format.

Changelog

• Release 0.3.0 on 2018-09-24
  • Minimum Clojure version is now 1.7 (because transducers)
  • The encode codepath completely rewritten to scrub out some of the wacky stuff I did 6 years ago. As a result it's 19x faster.

License

Copyright © 2018 Michael Gaare

Distributed under the Eclipse Public License, the same as Clojure.