测绘助手程序设计源码，包括圆曲线计算，道路坐标计算，缓和曲线盖梁长度计算，位于圆曲线斜交盖梁长度和两端点桩号及座标计算，坐标转换等功能-Mapping assistant programming source, including circular curve calculations, roads coordinate calculation, calculate the length of transition curve cap beam, located circular curve b