画图算法，包括数值微分法、中点画圆法、Bresenham画线、画圆算法等-Drawing algorithms, including numerical differential method, the midpoint drawcircle, Bresenham line draw, drawcircle algorithm

常用差值算法及数据排序：线性插值 光滑不等距插值 三次样条插值等。-Common difference algorithm and data sorting: linear interpolation smooth, equidistant interpolation cubic spline interpolation.

查找CAD自相交-check CAD PLine........................