diagonal matrix
Diagonal eigenvalues matrix, returned a matrix containing the eigenvalues of A or the generalized eigenvalues of the pair, (A,B), with multiplicity.
When the eigenvalues in D satisfy the equation, Av = λv, the eigenvalues are always real. In this case, MATLAB sorts them in descending order (from upper-left to lower-right) as long as A is real and symmetric, or complex Hermitian.