任意输入字符串，把相同的字符清楚掉，剩下的字符按原先的排序组合在一起-Any input string, the same character clear out the rest of the characters are combined together in the original sorting

使用matlab编程实现PCA算法，此算法经过测试，没有问题，可以放心使用-Use matlab programming PCA algorithm that has been tested, no problem, you can rest assured that use