function earth_longitude_range in Location 5.3
Same name and namespace in other branches
- 5 earth.inc \earth_longitude_range()
- 6.3 earth.inc \earth_longitude_range()
- 7.5 earth.inc \earth_longitude_range()
- 7.3 earth.inc \earth_longitude_range()
- 7.4 earth.inc \earth_longitude_range()
@todo This function uses earth_asin_safe so is not accurate for all possible parameter combinations. This means this function doesn't work properly for high distance values. This function needs to be re-written to work properly for larger distance values. See http://drupal.org/node/821628
2 calls to earth_longitude_range()
- 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 131 - 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_longitude_range($longitude, $latitude, $distance) {
// Estimate the min and max longitudes within $distance of a given location.
$long = deg2rad($longitude);
$lat = deg2rad($latitude);
$radius = earth_radius($latitude);
$angle = $distance / $radius;
$diff = earth_asin_safe(sin($angle) / cos($lat));
$minlong = $long - $diff;
$maxlong = $long + $diff;
if ($minlong < -pi()) {
$minlong = $minlong + pi() * 2;
}
if ($maxlong > pi()) {
$maxlong = $maxlong - pi() * 2;
}
return array(
rad2deg($minlong),
rad2deg($maxlong),
);
}