对角矩阵谢谢，我想应该也是。原文是“X、Yare the diagonal matrix of appropriate same order( that is the main diagonal elements of the matrix are not all zero, the remaining elements are all zero)”，其中的X、Y是我用来代指原文中的矩阵。还请不吝赐教。the diagonal matrix 是对角矩阵的意思啊!后面的话是解释什么叫对角矩阵!