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PHP library. Compute the bounding rectangle for the given lat / lng location.

I'm looking for a PHP Library / PHP Script that allows me to calculate the exact bounding box for a given center point (lat / lon).

Using the ellipsoid formula (f.ex. WGS84) would be great. I know there must be a library, but I cannot find it.

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The function is wrong after the // bearing bit, it should be like this:

function getBoundingBox($lat_degrees,$lon_degrees,$distance_in_miles) {

    $radius = 3963.1; // of earth in miles

    // bearings - FIX   
    $due_north = deg2rad(0);
    $due_south = deg2rad(180);
    $due_east = deg2rad(90);
    $due_west = deg2rad(270);

    // convert latitude and longitude into radians 
    $lat_r = deg2rad($lat_degrees);
    $lon_r = deg2rad($lon_degrees);

    // find the northmost, southmost, eastmost and westmost corners $distance_in_miles away
    // original formula from
    // http://www.movable-type.co.uk/scripts/latlong.html

    $northmost  = asin(sin($lat_r) * cos($distance_in_miles/$radius) + cos($lat_r) * sin ($distance_in_miles/$radius) * cos($due_north));
    $southmost  = asin(sin($lat_r) * cos($distance_in_miles/$radius) + cos($lat_r) * sin ($distance_in_miles/$radius) * cos($due_south));

    $eastmost = $lon_r + atan2(sin($due_east)*sin($distance_in_miles/$radius)*cos($lat_r),cos($distance_in_miles/$radius)-sin($lat_r)*sin($lat_r));
    $westmost = $lon_r + atan2(sin($due_west)*sin($distance_in_miles/$radius)*cos($lat_r),cos($distance_in_miles/$radius)-sin($lat_r)*sin($lat_r));


    $northmost = rad2deg($northmost);
    $southmost = rad2deg($southmost);
    $eastmost = rad2deg($eastmost);
    $westmost = rad2deg($westmost);

    // sort the lat and long so that we can use them for a between query        
    if ($northmost > $southmost) { 
        $lat1 = $southmost;
        $lat2 = $northmost;

    } else {
        $lat1 = $northmost;
        $lat2 = $southmost;
    }


    if ($eastmost > $westmost) { 
        $lon1 = $westmost;
        $lon2 = $eastmost;

    } else {
        $lon1 = $eastmost;
        $lon2 = $westmost;
    }

    return array($lat1,$lat2,$lon1,$lon2);
}


I got this feature thanks to: http://xoxco.com/clickable/php-getboundingbox

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This is a relatively simple problem to solve if you assume the bounding box runs east-west in one direction and north-south in the other. You can do latitude and longitude independently.

For latitude, sort the points from west to east. At this point, you should treat the list as a circular buffer. You need to check each point and find the one that is at the farthest next point. So, suppose ten points a 0 for nineif a 4 and five most distant, limiting the latitude of the field from five round up 4... Name them w and e



For longitude, you just need to find the northernmost and southernmost points, name them n and s...

Longitude w and e and latitude n and s define the bounding box.

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