说明：  测绘相关源码 包括：角度化弧度,弧度化角度,计算两点间的方位角,B_三次样条函数曲线拟合,贝赛尔曲线,
(Mapping related source code includes: angle radians, radians angle, calculate the azimuth between two points, B _ cubic spline function curve fitting, Bezier curve,)