用于测量与地图制图的高斯投影转换，提供了北京54、全国80、WGS84三个坐标系下的正算、反算。输出结果精确到小数点后7位。-for measuring and mapping the Gauss projection conversion, the Beijing 54, 80, three WGS84 coordinates the count is, anti-counting. Output accurate to seven decimal places.

自己总结的几种比较简单的反交错算法，算然不是最好的但是简单-Their summing up of several relatively simple de-interlacing algorithm, calculation of likelihood is not the best but simple

bspline样条曲线反算算法,有需要的可以借鉴一下-Bspline spline curve back calculation algorithm, in need can draw lessons it.