这是求两点之间的距离的程序，是用面向对象的方法做的-This is the distance between two points for the procedure is the use of object-oriented methods of

描述google_maps根据经纬度计算两点间距离的函数说明。-The descr iption google_maps descr iption of a function of the distance between two points is calculated based on latitude and longitude.

c++通过大圆算法求地球上两点之间距离，方位-c++ seek distance between two points on the earth, through the great circle azimuth algorithm