可计算任意多边形的质心和边缘凸点的坐标，该多边形由若干边缘坐标点确定。 给定的边缘坐标点越多，计算结果越精确。-The function applied to calculate the coordinate of barycenter and boundary embossses of a polygon,which is determined by boundary points. The points,the preciser of the result.