%生成随机矩阵并标准正交化
a= randn(3)
orth(a)
%随机投影进行降维
c=magic(3)
d=c*b
%验证距离
sim=squareform(pdist(d,'euclidean'))
sim=squareform(pdist(c,'euclidean'))
sim=squareform(pdist(b,'euclidean'))
参考文章：
http://xueshu.baidu.com/s?wd=paperuri%3A%28f13f07876aa5d65d72fe4722c627bc8f%29&filter=sc_long_sign&tn=SE_xueshusource_2kduw22v&sc_vurl=http%3A%2F%2Fwww.doc88.com%2Fp-3455353123460.html&ie=utf-8&sc_us=15522914053350141860