proximity

I'm trying to handle proximity search for a basic store locater in Django. Rather than haul PostGIS around with my app just so I can use GeoDjango's distance filter, I'd like to use the Spherical Law of Cosines distance formula in a model query. I'd like all of the calculations to be done in the database in one query, for efficiency. An example MySQL query from The Internet implementing the Spherical Law of Cosines like this: SELECT id, ( 3959 * acos( cos( radians(37) ) * cos( radians( lat ) ) * cos( radians( lng ) - radians(-122) ) + sin( radians(37) ) * sin( radians( lat ) ) ) ) AS distance

How does an application perform a proximity search? For example, a user types in a postal code, then the application lists all the businesses within 20 miles ordered by proximity. I want to build something like that in PHP and MySQL. Is this approach correct? Get the addresses for locations I'm interested in and store in my database Geocode all the addresses with Google's geocoding service Write a database query that includes Haversine formula to do the proximity search and ordering Is this OK? In step 3, I'm going to calculate the proximity for every query. Is it better to have a PROXIMITY

I want to use proximity sensor in my project. I searched for proximity sensor tutorial. And I found a sensor tutorial at http://www.vogella.com/articles/AndroidSensor/article.html#sensoroverview_manager . I tried to use proximity sensor as following code: @Override public void onSensorChanged(SensorEvent event) { if(event.sensor.getType() == Sensor.TYPE_PROXIMITY) { Toast.makeText(getApplicationContext(), "working", Toast.LENGTH_SHORT).show(); } } My Activity is implementing SensorEventListener . But its not working. Do I need to use any permission to use proximity sensor? Or My code is wrong

Can the iPhone SDK take advantage of the iPhone's proximity sensors? If so, why hasn't anyone taken advantage of them? I could picture a few decent uses. For example, in a racing game, you could put your finger on the proximity sensor to go instead of taking up screen real-estate with your thumb. Of course though, if this was your only option, then iPod touch users wouldn't be able to use the application. Does the proximity sensor tell how close you are, or just that something is in front of it? Assuming you mean the sensor that shuts off the screen when you hold it to your ear, I'm pretty