Calculate the center point of multiple latitude/longitude coordinates array

getLatLngCenter.php

 <?php

/**
 * Get Lat/Lng center from an coords array
 *
 * @param array $coords
 * @return float[]|int[]
 */
function getLatLngCenter(array $coords): array
{
    $num_coords = count($coords);

    $x = 0.0;
    $y = 0.0;
    $z = 0.0;

    foreach ($coords as $coord) {
        $lat = $coord[0] * pi() / 180;
        $lng = $coord[1] * pi() / 180;

        $a = cos($lat) * cos($lng);
        $b = cos($lat) * sin($lng);
        $c = sin($lat);

        $x += $a;
        $y += $b;
        $z += $c;
    }

    $x /= $num_coords;
    $y /= $num_coords;
    $z /= $num_coords;

    $lng = atan2($y, $x);
    $hyp = sqrt($x * $x + $y * $y);
    $lat = atan2($z, $hyp);

    return [
        $lat * 180 / pi(),
        $lng * 180 / pi(),
    ];
}