proximity_hash

Description:

proximity hash

Dart Proximity Hash #

Proximity Hash generates a set of geohashes that cover a circular area, given the center coordinates and the radius. Geohash is a public domain geocode system which encodes a geographic location into a short string of letters and digits and is used as unique identifies and to represent point data in databases.
For example the point
25.6953° S, 54.4367° W
will covert to
6g3mc626.
Geohash #
Proximity hash also comes with a geohash library forked from dart_geohash since it was not being actively maintained.
import 'package:proximity_hash/geohash.dart';
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Install #
To get this plugin, add proximity_hash as a dependency in your pubspec.yaml file. For example:
dependencies:
proximity_hash: ^1.1.0
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Usage #
To get all the geohashes within a radius of 5000 meters from the point 25.6953° S, 54.4367° W with precision 3 simply import the library and call createGeohashes(). The precision dictates how long and how many geohashes are returned. For
example a precision of 3 returns geohahses of length 3.
import 'package:proximity_hash/proximity_hash.dart';

List<String> proximityGeohashes = createGeohashes(48.864716, 2.349014, 5000, 3);

// proximityGeohashes == ["u0d","u09"]
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Performance #
Benchmark of createGeohashes for different precisions with radius 1000. Performance can become limiting starting at precision 9. Note that a larger radius will also decrease performance.



Precicion
Time




1
.0068 sec


2
.0068 sec


3
.0070 sec


4
.0070 sec


5
.0070 sec


6
.0079 sec


7
.0232 sec


8
.1664 sec


9
4.996 sec


10
153.5 sec



Issues #
Please file any issues, bugs or feature requests as an issue on our GitHub page.
Want to Contribute #
If you would like to contribute to the plugin (e.g. by improving the documentation, solving a bug or adding a cool new feature) submit a pull request.
Want to Support #




Based on proximityhash