此程序为ISODATA聚类算法的改进，主要是优化了其初始化，其初始化为两类，一类质心为极值最大点，另一类质心为离该质心最远的质心-This procedure is a clustering algorithm for the ISODATA , The original　method is improved by the initialization . let a maximum point

as the center of the first class,and let the centeris farthest that the first center as the center of the second class