计算两个地理坐标之间的距离

计算两个地理坐标之间的距离

Posted on 26/09/2010 by James Tang

下面这个函数(PHP实现)用于计算两个地理坐标之间的距离，主要用于处理源自Google地图的坐标数据。

验证数据：[48.856667, 2.350987], [38.895113, -77.036366]
验证结果：6172.4281776242KM

01

/**

02	* Calculate the distance between two coordinates.

03	* @param array $s, array(float:latitude, float: longitude)

04	* @param array $e, array(float:latitude, float: longitude)

05	* @return float, the distance

06

*/

07	function geo_distance( $s , $e ) {

08

09	//earth's mean radius in KM

10	$r = 6378.137;

11

12	$s [0] = deg2rad ( $s [0]);

13	$s [1] = deg2rad ( $s [1]);

14

15	$e [0] = deg2rad ( $e [0]);

16	$e [1] = deg2rad ( $e [1]);

17

18	$d0 = abs ( $s [0] - $e [0]);

19	$d1 = abs ( $s [1] - $e [1]);

20

21	$p = pow(sin( $d0 /2), 2) + cos ( $s [0]) * cos ( $e [0]) * pow(sin( $d1 /2), 2);

22

23	$ds = $r * 2 * asin(sqrt( $p ));

24

25	return $ds ;

26

}

MySQL Function

01	DELIMITER //

02	CREATE FUNCTION geo_distance(lat1 FLOAT , lng1 FLOAT , lat2 FLOAT , lng2 FLOAT ) RETURNS FLOAT

03

BEGIN

04

05	DECLARE r INT DEFAULT 6378137;

06	DECLARE s0 FLOAT ;

07	DECLARE s1 FLOAT ;

08	DECLARE e0 FLOAT ;

09	DECLARE e1 FLOAT ;

10

11	DECLARE d0 FLOAT ;

12	DECLARE d1 FLOAT ;

13

14	SET s0 = RADIANS(lat1);

15	SET s1 = RADIANS(lng1);

16	SET e0 = RADIANS(lat2);

17	SET e1 = RADIANS(lng2);

18

19	SET d0 = ABS (s0 - e0);

20	SET d1 = ABS (s1 - e1);

21

22	RETURN r * 2 * ASIN(SQRT(POW(SIN(d0/2),2) + COS(s0)*COS(e0)*POW(SIN(d1/2),2)));

23

24

END //

25

26	DELIMITER ;

About James Tang

Web Developer, focusing on large-scale web application and server architecture and implementation.

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