geo-indexing: efficiently calculating proximity based on latitude/longitude

Posted by AnC on Stack Overflow See other posts from Stack Overflow or by AnC
Published on 2010-03-17T07:48:41Z Indexed on 2010/03/17 7:51 UTC
Read the original article Hit count: 417

Filed under:

geolocation

My simple web app (WSGI, Python) supports text queries to find items in the database. Now I'd like to extend this to allow for queries like "find all items within 1 mile of {lat,long}".

Of course that's a complex job if efficiency is a concern, so I'm thinking of a dedicated external module that does indexing for geo-coordinates - sort of like Lucene would for text.

I assume a generic component like this already exists, but haven't been able to find anything so far. Any help would be greatly appreciated.

Related posts about geolocation

Which Devices Support Javascript Geolocation via navigator.geolocation ?

as seen on Stack Overflow - Search for 'Stack Overflow'
The iPhone supports geolocation in mobile Safari via the following call: navigator.geolocation.getCurrentPosition( function(pos){ var lat = pos.coords.latitude; var long = pos.coords.longitude; }, function(){ /* Handler if location could not be found */ } ); I'd like to build… >>> More
iPhone - Native App GeoLocation VS Web App GeoLocation

as seen on Stack Overflow - Search for 'Stack Overflow'
Here's my situation; I've built a very simple web app that looks up a users location and plots it on a Google map. Here's my code: http://pastebin.com/d3a185efd When I test it, my location is detected as being = 500 meters from where I actually stand. BUT When I open up Google Maps or Gowalla… >>> More
user disallowed geolocation - notify user second time

as seen on Stack Overflow - Search for 'Stack Overflow'
When trying to get geolocation on iPhone the first time - I declined. Every other time I want to get the location (before another reload of the page) I get no response (no error and no success): navigator.geolocation.getCurrentPosition( function (location) { ig_location.lat = location… >>> More
How to get my geolocation in bash

as seen on Stack Overflow - Search for 'Stack Overflow'
I am looking for a good geolocation api to use from bash. I want this call to return at the very minimum the name of the city I am in, and the state. I imagine that there must be some site I can curl, or some scripting language that has a package that works. The machine does not have a GPS, but it… >>> More
Geolocation Firefox accurate than iPhone Safari?

as seen on Stack Overflow - Search for 'Stack Overflow'
I just tested Geolocation on Firefox 3.6 and iPhone Safari (os 3.1.3), the result is interesting, firefox is more accurate than safari. any one got idea how to make iPhone Safari result more accurate. this is the code for testing: navigator.geolocation.getCurrentPosition(handler, {enableHighAccuracy:… >>> More

Developer IT