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Questions tagged [geohashing]

Geohash is a latitude/longitude encoding system using Base-32 characters.

Geohash is a latitude/longitude geocode system invented by Gustavo Niemeyer when writing the web service at geohash.org, and put into the public domain. It is a hierarchical spatial data structure which subdivides space, then interleaves the latitude and longitude information in a bitwise fashion.

Geohashes offer properties like arbitrary precision and the possibility of gradually removing characters from the end of the code to reduce its size (and gradually lose precision).

Nearby places will often (but not always) present similar prefixes. The longer a shared prefix is, the closer the two places are.

See https://en.wikipedia.org/wiki/Geohash

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Geohashing returns the same position for different hashes

I'm using Geohash library in python. Consider this code: $ python Python 2.7.6 (default, Jun 22 2015, 17:58:13) [GCC 4.8.2] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> import Geohash >>>…
Filip
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Geohashing vs SearchAPI for geospatial querying using datastore

I am creating an appEngine application in python that will need to perform efficient geospatial queries on datastore data. An example use case would be, I need to find the first 20 posts within a 10 mile radius of the current user. Having done…
BuddyD
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Why Geohash named `xxxhash` when it's actually an encoding algorithm?

A geohash is a convenient way of expressing a location (anywhere in the world) using a short alphanumeric string, with greater precision obtained with longer strings. When I learn it the first time I was confused by its name. It's totally…
zhumengzhu
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Geodata Querying Optimisations

I am planning to write a Node.js-powered RESTful web service that I will use for a mobile application which provides some sort of location based features. The most basic use case is going to look something like this: the user can create a resource…
Alexandru Pele
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Fast method of Geospatial indexing of half million polygons in Lucene

I am trying to find intersecting geo-hashes(upto precision length 6) of around half million polygons. For every polygon I have to find all the geohashes(upto precision length 6) inside that polygon and index it. I have tried using postgis st_geohash…
S. A. Kumar
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Kibana doesn't show results on tile map

I have approximately 3300 documents with geo_point typed field filled. When I try to visualize my documents on the tile map, kibana says "no results found". I've already tried putting coordinates as: - geohash in string - [lon, lat] array -…
Anna Prosvetova
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Geohash: Using libgeohash to find neighbors

In my application I am storing Geohash of all users in a table and want to find neighbors of a user using those Geohashes. As per info I gathered about Geohash on Wiki: When used in a database, the structure of geohashed data has two advantages.…
Atul
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Using Kibana4 Tile Map with Geo-Points

I'm using Logstash to insert a location attribute into my logs that are going into ElasticSearch: "location" : { "lat":31.07, "lon":-82.09 } I'm then setting up a mapping to tell ElasticSearch it's a Geo-Point. I'm not exactly sure how this…
R. P. Dillon
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Geohash not generated in Elastic search

I have created an index as follows: POST /cabtrails { "settings" : { "number_of_shards" : 3, "number_of_replicas" : 1 }, "mappings" : { "cabtrail" :{ "properties" : { "location": { "type": "geo_point", …
spiralarchitect
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Use of unresolved identifier when testing a public class

I’m unable to unit my class because Xcode doesn’t see my main class under test target. My swift module is defined as public public class Geohash { public static func encodeGeoHash(latitude: Double, longitude: Double, precision: Int = 12) ->…
Maxim Veksler
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Geolocation or geohash grid/bucket key value store possible with Elastic Search?

Is it possible to use Elastic Search as a geohash key-value store? For example, I'd like to store moving objects into Elastic Search, using their geohash as an index. Write speed isn't too important, just read speed. So I'd like to use a key-value…
JeffLL
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ElasticSearch geolocation and performance

I was wondering: what's best for indexing places' geolocation ? Geohash or lon/lat ? I search places based on the distance between the user and the place so what's best for ElasticSearch ? I think Geohash is more powerful but I may be wrong...
user3491456
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Cassandra CQL 3 - Prefix Select

is there a way to perform a select based on a string prefix using CQL3? For example, consider the following table: Key | Value ------------ ABC | 0x01 ABD | 0x02 BBB | 0x03 I want to select all the keys with the prefix 'AB'. The database will be…
mariolpantunes
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Advantages of Geohashing

Can someone explain what are positives of using geohashing? Why not split the map in squares of some size and each square has x,y index and we can keep a map from the index of the square to the data in it. This way it's easier to find data in some…
user2474033
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geoHash -ing for close points on each side of the equator

I am working on a project (java using NetBeans) which at some point needs to process map data. I have got Esri shape files for whole UK and need to create one dimensional index using geoHash as efficiency is a big factor in my project. Since I need…
user1372020
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