Afstand berekenen tussen postcodes

Voor sitedeals leden
---------------------------

$postcode = '1234AB';

$this->data['googleapi']['url'] = 'http://maps.google.com/maps/api/geocode/xml?address='.urlencode($postcode.",Nederland").'&sensor=false';
$this->data['xml'] = simplexml_load_file($this->data['googleapi']['url']);
$this->data['coordinates'] = $this->data['xml']->result->geometry->location;

$this->data['lat'] = $this->data['coordinates']->lat;
$this->data['lng'] = $this->data['coordinates']->lng;

$this->data['lat1'] = deg2rad(floatval($this->data['lat']));
$this->data['lat2'] = deg2rad(floatval($result[0]['lat'])); //hier de lat van eerdere opgehaalde positie van andere postcode
$this->data['lng1'] = deg2rad(floatval($this->data['lng']));
$this->data['lng2'] = deg2rad(floatval($result[0]['lng'])); //hier de lng van eerdere opgehaalde positie van andere postcode

$this->data['earthradius'] =	6372.797; // mean radius of Earth in km
$this->data['dlat'] =	$this->data['lat2'] - $this->data['lat1'];
$this->data['dlng'] =	$this->data['lng2'] - $this->data['lng1'];
$this->data['a'] =	sin($this->data['dlat'] / 2) * sin($this->data['dlat'] / 2) + cos($this->data['lat1']) * cos($this->data['lat2']) * sin($this->data['dlng'] / 2) * sin($this->data['dlng'] / 2);
$this->data['c'] =	2 * asin(min(1, sqrt($this->data['a'])));
$this->data['afstand'] =	$this->data['earthradius']* $this->data['c'];