function earth_latitude_range in Location 5

Same name and namespace in other branches

1. 5.3 earth.inc \earth_latitude_range()
2. 6.3 earth.inc \earth_latitude_range()
3. 7.5 earth.inc \earth_latitude_range()
4. 7.3 earth.inc \earth_latitude_range()
5. 7.4 earth.inc \earth_latitude_range()

3 calls to earth_latitude_range()

location_search_results in ./location.module

location_views_filter_handler_proximity in contrib/location_views/location_views.module

_location_nearby_postalcodes in ./location.inc

This is the main logic-level function for performing proximity postal-code searches. It calls a number of helper functions for finding postal_code results in each country, narrowing down results, formatting the returned array, and sorting the returned…

File

./earth.inc, line 129

Code

function earth_latitude_range($longitude, $latitude, $distance) {

  // Estimate the min and max latitudes within $distance of a given location.
  $long = deg2rad($longitude);
  $lat = deg2rad($latitude);
  $radius = earth_radius($latitude);
  $angle = $distance / $radius;
  $minlat = $lat - $angle;
  $maxlat = $lat + $angle;
  $rightangle = pi() / 2;
  if ($minlat < -$rightangle) {

    // wrapped around the south pole
    $overshoot = -$minlat - $rightangle;
    $minlat = -$rightangle + $overshoot;
    if ($minlat > $maxlat) {
      $maxlat = $minlat;
    }
    $minlat = -$rightangle;
  }
  if ($maxlat > $rightangle) {

    // wrapped around the north pole
    $overshoot = $maxlat - $rightangle;
    $maxlat = $rightangle - $overshoot;
    if ($maxlat < $minlat) {
      $minlat = $maxlat;
    }
    $maxlat = $rightangle;
  }
  return array(
    rad2deg($minlat),
    rad2deg($maxlat),
  );
}