/// <summary>
/// 返回两点球面距离
/// </summary>
/// <param name="A"></param>
/// <param name="B"></param>
/// <returns>返回两点距离，单位千米</returns>
public static double distance(JWD A, JWD B)
{
double dx = (B.m_RadLo - A.m_RadLo) * A.Ed;
double dy = (B.m_RadLa - A.m_RadLa) * A.Ec;
double outresult = Math.Sqrt(dx * dx + dy * dy);
return(outresult / 1000);
}
public static double distance(
double longitude1, double latitude1,
double longitude2, double latitude2)
{
JWD A = new JWD(longitude1, latitude1);
JWD B = new JWD(longitude2, latitude2);
return(distance(A, B));
}
//! 已知点A经纬度，根据B点据A点的距离，和方位，求B点的经纬度， 正北方向是0度
/*!
* \param A 已知点A
* \param distance B点到A点的距离
* \param angle B点相对于A点的方位
* \return B点的经纬度坐标
*/
public static JWD GetJWDB(JWD A, double distance, double angle)
{
double dx = distance * 1000 * Math.Sin(angle * Math.PI / 180);
double dy = distance * 1000 * Math.Cos(angle * Math.PI / 180);
//double dx = (B.m_RadLo - A.m_RadLo) * A.Ed;
//double dy = (B.m_RadLa - A.m_RadLa) * A.Ec;
double BJD = (dx / A.Ed + A.m_RadLo) * 180 / Math.PI;
double BWD = (dy / A.Ec + A.m_RadLa) * 180 / Math.PI;
JWD B = new JWD(BJD, BWD);
return(B);
}
//! 计算点A 和 点B的经纬度，求他们的距离和点B相对于点A的方位
/*!
* \param A A点经纬度
* \param B B点经纬度
* \param angle B相对于A的方位, 不需要返回该值，则将其设为空
* \return A点B点的距离
*/
public static double distance(JWD A, JWD B, ref double angle)
{
double dx = (B.m_RadLo - A.m_RadLo) * A.Ed;
double dy = (B.m_RadLa - A.m_RadLa) * A.Ec;
double outresult = Math.Sqrt(dx * dx + dy * dy);
if (angle != 390)
{
if (dx == 0.0)
{
angle = 0;
}
else if (dy == 0.0)
{
angle = 90;
}
else
{
angle = Math.Atan(Math.Abs(dx / dy)) * 180 / Math.PI;
}
// 判断象限
double dLo = B.m_Longitude - A.m_Longitude;
double dLa = B.m_Latitude - A.m_Latitude;
if (dLo > 0 && dLa <= 0)
{
angle = (90 - angle) + 90;
}
else if (dLo <= 0 && dLa < 0)
{
angle = angle + 180;
}
else if (dLo < 0 && dLa >= 0)
{
angle = (90 - angle) + 270;
}
}
return(outresult / 1000);
}
//! 已知点A经纬度，根据B点据A点的距离，和方位，求B点的经纬度,正北方向为0度
/*!
* \param longitude 已知点A经度
* \param latitude 已知点A纬度
* \param distance B点到A点的距离
* \param angle B点相对于A点的方位
* \return B点的经纬度坐标
*/
public static JWD GetJWDB(double longitude, double latitude, double distance, double angle)
{
JWD A = new JWD(longitude, latitude);
return(GetJWDB(A, distance, angle));
}
