CODEWITHSUNDEEP
javascriptjsongeolocationgeocoding
socialMatrix
socialMatrix

Reputation: 1443

Geolocation: filter by proximity

I have a list of users from across the world in JSON format. Each item in the list has a location information.

  1. How do I convert these locations to proper longitude and latitude?
  2. How do I filter these locations to get only locations within 50 miles of my current location (assuming I know how to get current longitude and latitude).

Is there a Service that I can use?

Do I really need to convert these locations to longitude and latitudes? Essentially all I want to do is find locations withing 50 miles of current location and ignore others.

Upvotes: 1

Views: 1956

Answers (2)

j0nes
j0nes

Reputation: 8099

You can use the free geonames.org webservice for that. There is a search method available where you can give a location name and get latitude and longitude for any location. Be aware that there may be multiple locations with the same name available. See the example here: http://api.geonames.org/searchJSON?q=london&maxRows=10&username=demo

For your second question, there are multiple approaches. The basic algorithms are outlined in this question, but probably the easiest way is to use the Google Maps API (see second answer to this question).

Upvotes: 3

Giacomo1968
Giacomo1968

Reputation: 26066

I’ve done this in the past, at it’s not something one can do simply with just JavaScript & JSON. The best way is to create a MySQL database that uses spatial Point commands. If you want JavaScript & JSON, then you would have to create a webservice—using PHP for example—to manage the queries between the JavaScript & MySQL database. It seems daunting at first, but once you get the hang of it, it’s quite cool. I recommend reading this site to understand the basics.

Upvotes: 1

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