FlexibleGeohash 0.1.1

FlexibleGeohash 0.1.1

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Maintained by Koji Murata.

FlexibleGeohash 0.1.1

  • By
  • Koji Murata

FlexibleGeohash Build Status SwiftPM compatible Cocoapods License

FlexibleGeohash is a very fast library for handling Geohash.
Geohash is usually encoded in base32, but it can be encoded in base2/4/8/16/32.

I used mmcloughlin/geohash and michael-groble/Geohash as a reference to create this library.
Thank you so much!

Benchmark

https://gist.github.com/malt03/7ac251ea0f47f4874c986a6720be3acf

decode 1,000,000 times

library time
malt03/FlexibleGeohash 0.9568190574645996
maximveksler/GeohashKit 1.2289820909500122
michael-groble/Geohash 1.4453539848327637
nh7a/Geohash 9.60263705253601

encode 1,000,000 times

library time
malt03/FlexibleGeohash 0.22908806800842285
maximveksler/GeohashKit 0.9335179328918457
michael-groble/Geohash 0.3671489953994751
nh7a/Geohash 114.44236898422241

get neighbors 100,000 times

library time
malt03/FlexibleGeohash 0.33184492588043213
maximveksler/GeohashKit 3.7601670026779175
michael-groble/Geohash 0.33417296409606934
nh7a/Geohash 103.8870279788971

Usage

Encoding

let appleCoordinate = CLLocationCoordinate2D(latitude: 37.331667, longitude: -122.030833)
var apple = Geohash(coordinate: appleCoordinate, precision: 7)
_ = apple.hash() // 9q9hrh5
apple.precision = 4
_ = apple.hash() // 9q9h
apple.precision = 10
_ = apple.hash() // 9q9hrh5ber

Decoding

var apple = Geohash(hash: "9q9hrh5")
print(apple.region().mk())
// MKCoordinateRegion(
//     center: CLLocationCoordinate2D(latitude: 37.33222961425781, longitude: -122.03132629394531),
//     span: MKCoordinateSpan(latitudeDelta: 0.001373291015625, longitudeDelta: 0.001373291015625)
// )
apple.precision = 1
print(apple.region().mk())
// MKCoordinateRegion(
//     center: CLLocationCoordinate2D(latitude: 59.83154296875, longitude: -99.53201293945312),
//     span: __C.MKCoordinateSpan(latitudeDelta: 45.0, longitudeDelta: 45.0)
// )

Getting neighbors

var apple = Geohash(hash: "9q9h")
_ = apple.neighbor(.north).hash() // 9q9j
_ = apple.neighbors().map { $0.hash() } // ["9q9k", "9q9m", "9q97", "9q9j", "9q95", "9q8u", "9q8v", "9q8g"]
apple.precision = 1
_ = apple.neighbors().map { $0.hash() } // ["d", "f", "6", "c", "3", "8", "b", "2"]
apple.precision = 7
_ = apple.neighbors().map { $0.hash() } // ["9q9h001", "9q9h003", "9q95bpc", "9q9h002", "9q95bpb", "9q8upbp", "9q8upbr", "9q8gzzz"]

Using with base8

Naturally, Geohash encoded by something other than base32 is not compatible with the one encoded by base32.

let appleCoordinate = CLLocationCoordinate2D(latitude: 37.331667, longitude: -122.030833)
var apple = Geohash(coordinate: appleCoordinate, precision: 21, encoding: .base8)
_ = apple.hash() // 233114136012515572573
apple.precision = 4
_ = apple.hash() // 2331

apple.encoding = .base32
apple.precision = 12
_ = apple.hash() // 9q9hrh5berpg

_ = Geohash(hash: "2331", encoding: .base8).region().mk()
// MKCoordinateRegion(
//     center: CLLocationCoordinate2D(latitude: 37.96875, longitude: -120.9375),
//     span: MKCoordinateSpan(latitudeDelta: 2.8125, longitudeDelta: 5.625)
// )

Getting Span for precision

_ = Geohash.span(precision: 7) // latitude: 0.001373291015625, longitude: 0.001373291015625
_ = Geohash.span(precision: 7, encoding: .base2) // latitude: 22.5, longitude: 22.5

Setting default precision / encoding

Geohash.defaultPrecision = 4
Geohash.defaultEncoding = .base2
_ = Geohash(coordinate: LatLng(37.331667, -122.030833)).hash() // "0100"
_ = Geohash(hash: "0100").region().mk()
// MKCoordinateRegion(
//     center: CLLocationCoordinate2D(latitude: 22.5, longitude: -135),
//     span: MKCoordinateSpan(latitudeDelta: 45, longitudeDelta: 90)
// )

Installation

SwiftPM (Recommended)

  • On Xcode, click File > Swift Packages > Add Package Dependency...
  • Input https://github.com/malt03/FlexibleGeohash.git

CocoaPods

  • Insert pod 'FlexibleGeohash' to your Podfile.
  • Run pod install.