经纬度转换为三维坐标

// 经纬度转换为球坐标double torad(double deg){return deg/180*acos(-1);}void get_coordinate(double R,double lat,double lng,double &x,double &y,double z){lat = torad(lat);lng = torad(lng);x = R*cos(lat)*cos(lng);y = R*cos(lat)*sin(lng);z = R*sin(lat);}