百度地图计算两坐标点之间距离计算
public
class
BaiDuMap {
`
static`double
DEF_PI =
3.14159265359
;
// PI
`
static`double
DEF_2PI=
6.28318530712
;
// 2*PI
`
static`double
DEF_PI180=
0.01745329252
;
// PI/180.0
`
static`double
DEF_R =
6370693.5
;
// radius of earth
`
//适用于近距离`
`
public`static
double
GetShortDistance(
double
lon1,
double
lat1,
double
lon2,
double
lat2)
`
{`
`
double`ew1, ns1, ew2, ns2;
`
double`dx, dy, dew;
`
double`distance;
`
// 角度转换为弧度`
`
ew1 = lon1 * DEF_PI180;`
`
ns1 = lat1 * DEF_PI180;`
`
ew2 = lon2 * DEF_PI180;`
`
ns2 = lat2 * DEF_PI180;`
`
// 经度差`
`
dew = ew1 - ew2;`
`
// 若跨东经和西经180 度,进行调整`
`
if`(dew > DEF_PI)
`
dew = DEF_2PI - dew;`
`
else`if
(dew < -DEF_PI)
`
dew = DEF_2PI + dew;`
`
dx = DEF_R Math.cos(ns1) dew; `// 东西方向长度(在纬度圈上的投影长度)
`
dy = DEF_R * (ns1 - ns2); `// 南北方向长度(在经度圈上的投影长度)
`
// 勾股定理求斜边长`
`
distance = Math.sqrt(dx dx + dy dy);`
`
return`distance;
`
}`
`
//适用于远距离`
`
public`static
double
GetLongDistance(
double
lon1,
double
lat1,
double
lon2,
double
lat2)
`
{`
`
double`ew1, ns1, ew2, ns2;
`
double`distance;
`
// 角度转换为弧度`
`
ew1 = lon1 * DEF_PI180;`
`
ns1 = lat1 * DEF_PI180;`
`
ew2 = lon2 * DEF_PI180;`
`
ns2 = lat2 * DEF_PI180;`
`
// 求大圆劣弧与球心所夹的角(弧度)`
`
distance = Math.sin(ns1) Math.sin(ns2) + Math.cos(ns1) Math.cos(ns2) * Math.cos(ew1 - ew2);`
`
// 调整到[-1..1]范围内,避免溢出`
`
if`(distance >
1.0
)
`
distance = `1.0
;
`
else`if
(distance < -
1.0
)
`
distance = -`1.0
;
`
// 求大圆劣弧长度`
`
distance = DEF_R * Math.acos(distance);`
`
return`distance;
`
}`
`
public`static
void
main(String[] args) {
`
double`mLat1 =
39.90923
;
// point1纬度
`
double`mLon1 =
116.357428
;
// point1经度
`
double`mLat2 =
39.90923
;
// point2纬度
`
double`mLon2 =
116.397428
;
// point2经度
`
double`distance = BaiDuMap.GetShortDistance(mLon1, mLat1, mLon2, mLat2);
`
System.out.println(distance);`
`
}`
}
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