League\Geotools\Vertex\Vertex::initialBearing PHP Метод

    public function initialBearing()
    {
        Ellipsoid::checkCoordinatesEllipsoid($this->from, $this->to);
        $latA = deg2rad($this->from->getLatitude());
        $latB = deg2rad($this->to->getLatitude());
        $dLng = deg2rad($this->to->getLongitude() - $this->from->getLongitude());
        $y = sin($dLng) * cos($latB);
        $x = cos($latA) * sin($latB) - sin($latA) * cos($latB) * cos($dLng);
        return (double) (rad2deg(atan2($y, $x)) + 360) % 360;
    }