利用换位矩阵实现了多个矩阵做张量积任意个矩阵可交换,从而把两个矩阵做张量积交换后数值半径相等推广到多个矩阵。
Multiple arbitrary matrices can be commuted with the help of permute matrix when these matrices do tensor product. And that the equality of numerical radius after tensor products of two matrices is commuted is extented to more matrices.