The only valid matrix positions for a DIA or ZDI matrix are the diagonal elements; for an UPP or LOW matrix, the valid positions are the elements above or below the diagonal; and for a symmetric ...

This paper proposes a novel shrinkage estimator for high-dimensional covariance matrices by extending the Oracle Approximating Shrinkage (OAS) of Chen et al. (2009) to target the diagonal elements of ...

A procedure is presented for rapidly computing the diagnonal elements of a large numerator relationship matrix, say $\mathbf {A}$. It also generates a lower triangular matrix, say $\mathbf {L}$, ...

K. R. James, Convergence of Matrix Iterations Subject to Diagonal Dominance, SIAM Journal on Numerical Analysis, Vol. 10, No. 3 (Jun., 1973), pp. 478-484 ...