diag_mat.md

形如$\Lambda=\left(\begin{matrix}\lambda_1&0&\cdots&0\\0&\lambda_2&\cdots&0\\\vdots&\vdots&&\vdots\\0&0&\cdots&\lambda_n\end{matrix}\right)$的方阵称为对角矩阵(或对角阵

记作$\Lambda=diag(\lambda_1,\lambda_2,\cdots,\lambda_n)$