PHP sphere_distance Examples

Example #1

File: sphere-distance.php Project: zmwebdev/PHPcookbook-code-3ed

<?php

function sphere_distance($lat1, $lon1, $lat2, $lon2, $radius = 6378.135)
{
    $rad = doubleval(M_PI / 180.0);
    $lat1 = doubleval($lat1) * $rad;
    $lon1 = doubleval($lon1) * $rad;
    $lat2 = doubleval($lat2) * $rad;
    $lon2 = doubleval($lon2) * $rad;
    $theta = $lon2 - $lon1;
    $dist = acos(sin($lat1) * sin($lat2) + cos($lat1) * cos($lat2) * cos($theta));
    if ($dist < 0) {
        $dist += M_PI;
    }
    return $dist = $dist * $radius;
    // Default is Earth equatorial radius in kilometers
}
// NY, NY (10040)
$lat1 = 40.858704;
$lon1 = -73.928532;
// SF, CA (94144)
$lat2 = 37.758434;
$lon2 = -122.435126;
$dist = sphere_distance($lat1, $lon1, $lat2, $lon2);
// It's about 2570 miles from NYC to SF
// $formatted is 2570.18
$formatted = sprintf("%.2f", $dist * 0.621);
// Format and convert to miles

Example #2

File: mars-distance.php Project: zmwebdev/PHPcookbook-code-3ed

<?php

$martian_radius = 3397;
$dist = sphere_distance($lat1, $lon1, $lat2, $lon2, $martian_radius);
$formatted = sprintf("%.2f", $dist * 0.621);
// Format and convert to miles