Re: longitude/latitude function

Edward: We use a dealer locator. I would suggest one thing if you have a lot of data, hits, namely to pre-calculate the lat/long in radians and store radians in the database. This would speed up the script. _justin Edward Peloke wrote: > > Thanks Aaron, > > If you don't mind me asking, where did you get it? It seems to give a > better answer than my function. > > Thanks! > Eddie > > -----Original Message----- > From: Aaron Gould [mailto:webdevel@partscanada.com] > Sent: Friday, November 15, 2002 11:04 AM > To: Edward Peloke; php-general@lists.php.net > Subject: Re: [PHP] longitude/latitude function > > Try this snippet... I can't vouch for its accuracy since I am not a > mathematician: > > <? > // Function takes latitude and longitude of two places as input > // and prints the distance in miles and kms. > function calculateDistance($lat1, $lon1, $lat2, $lon2) > // Convert all the degrees to radians > $lat1 = deg2rad($lat1); > $lon1 = deg2rad($lon1); > $lat2 = deg2rad($lat2); > $lon2 = deg2rad($lon2); > > // Find the deltas > $delta_lat = $lat2 - $lat1; > $delta_lon = $lon2 - $lon1; > > // Find the Great Circle distance > $temp = pow(sin($delta_lat / 2.0), 2) + cos($lat1) * cos($lat2) * > pow(sin($delta_lon / 2.0), 2); > > $EARTH_RADIUS = 3956; > > $distance = ($EARTH_RADIUS * 2 * atan2(sqrt($temp), sqrt(1 - $temp)) * > 1.6093); > > return $distance; > } > ?> > > -- > Aaron Gould > agould@partscanada.com > Web Developer > Parts Canada > > ----- Original Message ----- > From: "Edward Peloke" <epeloke@echoman.com> > To: <php-general@lists.php.net> > Sent: Friday, November 15, 2002 11:20 AM > Subject: [PHP] longitude/latitude function > > > Has anyone ever written a php function to take the longitude and latitude > of > > two destinations and calculate the distance? > > > > I am working on one but the output is just a little off. > > > > Thanks, > > Eddie > > > > > > -- > > PHP General Mailing List (http://www.php.net/) > > To unsubscribe, visit: http://www.php.net/unsub.php > > -- > PHP General Mailing List (http://www.php.net/) > To unsubscribe, visit: http://www.php.net/unsub.php > > -- > PHP General Mailing List (http://www.php.net/) > To unsubscribe, visit: http://www.php.net/unsub.php -- Justin Farnsworth Eye Integrated Communications 321 South Evans - Suite 203 Greenville, NC 27858 | Tel: (252) 353-0722