Coordinate conversion between Tencent and Baidu in PHP

public function coordinate_switch($a,$b){//百度转腾讯坐标转换
    $x = (double)$b - 0.0065;
    $y = (double)$a - 0.006;
    $x_pi = 3.14159265358979324;
    $z = sqrt($x * $x+$y * $y) - 0.00002 * sin($y * $x_pi);
    $theta = atan2($y,$x) - 0.000003 * cos($x*$x_pi);
    $gb = number_format($z * cos($theta),15);
    $ga = number_format($z * sin($theta),15);
    return ['Latitude'=>$ga,'Longitude'=>$gb];
}
public function coordinate_switchf($a,$b){//腾讯转百度坐标转换
    $x = (double)$b ;
    $y = (double)$a;
    $x_pi = 3.14159265358979324;
    $z = sqrt($x * $x+$y * $y) + 0.00002 * sin($y * $x_pi);
    $theta = atan2($y,$x) + 0.000003 * cos($x*$x_pi);
    $gb = number_format($z * cos($theta) + 0.0065,6);
    $ga = number_format($z * sin($theta) + 0.006,6);
    return ['Latitude'=>$ga,'Longitude'=>$gb];
}