Diagonal Matrix

Definition: Diagonal Matrix

A diagonal matrix is a square matrix $M\in F^{n\times n}$ which has non-zero entries only on its diagonal.

$$\left[\begin{array}{ccc}{\lambda }_1& \cdots & 0_F\\ ⋮& \ddots & ⋮\\ 0_F& \cdots & {\lambda }_n\end{array}\right]$$

NOTATION

$$\mathrm{diag}({\lambda }_1,\cdots ,{\lambda }_n)$$