function caculateLL
(lat1
, lng1
, lat2
, lng2
)
{
var radLat1
= lat1
* Math
.PI
/
180.0
;
var radLat2
= lat2
* Math
.PI
/
180.0
;
var a
= radLat1
- radLat2
;
var b
= lng1
* Math
.PI
/
180.0
- lng2
* Math
.PI
/
180.0
;
var s
=
2
* Math
.asin
(Math
.sqrt
(Math
.pow
(Math
.sin
(a
/
2
),
2
)
+ Math
.cos
(radLat1
)
* Math
.cos
(radLat2
)
* Math
.pow
(Math
.sin
(b
/
2
),
2
)));
s
= s
*
6378.137
;
s
= Math
.round
(s
*
10000
)
/
10000
;
return s
};