geometry:convexhull-by-graham-scan

说明:graham-scan算法计算点集凸包参数: pts:点表

用法:
 (geometry:convexhull-by-graham-scan pts)

参数:1 pts : 多个坐标点列表;

返回值:凸包点表

示例:
(geometry:convexhull-by-graham-scan '(pt1 pt2 pt3 ...))