百度地图坐标转换为腾讯地图坐标

function convertBtQ ($lat, $lng)
	{
		if (empty($lat) && empty($lng)) {
			return false;
		}

		$x_pi  = 3.14159265358979324 * 3000.0 / 180.0;
		$x     = $lng - 0.0065;
		$y     = $lat - 0.006;
		$z     = sqrt($x * $x + $y * $y) - 0.00002 * sin($y * $x_pi);
		$theta = atan2($y, $x) - 0.000003 * cos($x * $x_pi);
		$lng   = $z * cos($theta);
		$lat   = $z * sin($theta);

		return ['lat' => $lat, 'lng' => $lng];
	}