说明：  一般统计数据中有很多变量，采用组成分分析法，可以既有效抓住有效信息，又实现降维。本程序采用实例，来说明此方法。
(General statistics, there are many variables, sub-components analysis, can only effectively capture useful information, but also to achieve dimensionality reduction. The program uses examples to illustrate this method. )