function earth_distance_sql in Location 5.3

Same name and namespace in other branches

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

2 calls to earth_distance_sql()

location_views_filter_handler_proximity in contrib/location_views/location_views.module

_location_search in contrib/location_search/location_search.module

Implementation of hook_search(). (forwarded from location.module)

File

./earth.inc, line 109

Trigonometry for calculating geographical distances. All function arguments and return values measure distances in metres and angles in degrees. The ellipsoid model is from the WGS-84 datum. Ka-Ping Yee, 2003-08-11

Code

function earth_distance_sql($longitude, $latitude, $tbl_alias = '') {

  // Make a SQL expression that estimates the distance to the given location.
  $long = deg2rad($longitude);
  $lat = deg2rad($latitude);
  $radius = earth_radius($latitude);

  // If the table alias is specified, add on the separator.
  $tbl_alias = empty($tbl_alias) ? $tbl_alias : $tbl_alias . '.';
  $coslong = cos($long);
  $coslat = cos($lat);
  $sinlong = sin($long);
  $sinlat = sin($lat);
  return "(IFNULL(ACOS({$coslat}*COS(RADIANS({$tbl_alias}latitude))*({$coslong}*COS(RADIANS({$tbl_alias}longitude)) + {$sinlong}*SIN(RADIANS({$tbl_alias}longitude))) + {$sinlat}*SIN(RADIANS({$tbl_alias}latitude))), 0.00000)*{$radius})";
}