//! 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 /*!
public static double angle(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 out = Math.sqrt(dx * dx + dy * dy);
double angle = 0.0;
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(angle);
}
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);
}
//! 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 /*!
public static JWD GetJWDB(double longitude, double latitude, double distance, double angle)
{
JWD A = new JWD(longitude, latitude);
return(GetJWDB(A, distance, angle));
}
