<?php
#The following software is distributed free of charge using the BSD Licence:
#
#
# Copyright (c) 2008, Corra Communications
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#     * Redistributions of source code must retain the above copyright
#       notice, this list of conditions and the following disclaimer.
#     * Redistributions in binary form must reproduce the above copyright
#       notice, this list of conditions and the following disclaimer in the
#       documentation and/or other materials provided with the distribution.
#     * Neither the name of the organization nor the
#       names of its contributors may be used to endorse or promote products
#       derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY CORRA COMMUNICATIONS ``AS IS'' AND ANY
# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL CORRA COMMUNICATIONS BE LIABLE FOR ANY
# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

function calc_dist($latitude1, $longitude1, $latitude2, $longitude2) {
$thet = $longitude1 - $longitude2;
$dist = (sin(deg2rad($latitude1)) * sin(deg2rad($latitude2))) + (cos(deg2rad($latitude1)) * cos(deg2rad($latitude2)) * cos(deg2rad($thet)));
$dist = acos($dist);
$dist = rad2deg($dist);
$kmperlat = 111.325; // Kilometers per degree latitude constant
$dist = $dist * $kmperlat;
return (round($dist));
}

//Calculates distance in KM between postcodes
function postcode_dist($postcode1,$postcode2, $suburb1 = '', $suburb2 = '') {
//Get lat and lon for postcode 1
$extra = "";
if ($suburb1 != '') {
$extra = " and suburb = '$suburb1'";
}
$sqlquery = "SELECT * FROM postcode_db WHERE lat <> 0 and lon <> 0 and postcode = '$postcode1'$extra";
$res = mysql_query($sqlquery);
$num = mysql_num_rows($res);


//Get lat and lon for postcode 2

$extra = "";
if ($suburb2 != '') {
$extra = " and suburb = '$suburb2'";
}
$sqlquery = "SELECT * FROM postcode_db WHERE lat <> 0 and lon <> 0 and postcode = '$postcode2'$extra";
$res1 = mysql_query($sqlquery);
$num1 = mysql_num_rows($res1);

if ($num != 0 && $num1 != 0) {
//proceed
$lat1 = mysql_result($res,0,"lat");
$lon1 = mysql_result($res,0,"lon");
$lat2 = mysql_result($res1,0,"lat");
$lon2 = mysql_result($res1,0,"lon");
$dist = calc_dist($lat1, $lon1, $lat2, $lon2);
if (is_numeric($dist)) {
return $dist;
}
else
{
return "Unknown";
}
}
else
{
return "Unknown";
}
}
?>


<?php
//Example Usage ------------------------------------------------------

$start = microtime(true);

echo "Distance: " . postcode_dist('5019','5015') . "\n Render time: ";

$end = microtime(true);
echo $end - $start;

//End Example --------------------------------------------------------
?>