The QR algorithm for unitary Hessenberg matrices
Journal of Computational and Applied Mathematics
Matrix computations (3rd ed.)
An Orthogonal Similarity Reduction of a Matrix into Semiseparable Form
SIAM Journal on Matrix Analysis and Applications
Structures preserved by the QR-algorithm
Journal of Computational and Applied Mathematics
A multiple shift QR-step for structured rank matrices
Journal of Computational and Applied Mathematics
Hi-index | 7.29 |
In this paper we investigate some classes of structures that are preserved by applying a (shifted) QR-step on a matrix A. We will handle two classes of such structures: the first we call polynomial structures, for example a matrix being Hermitian or Hermitian up to a rank one correction, and the second we call rank structures, which are encountered for example in all kinds of what we could call Hessenberg-like and lower semiseparable-like matrices. An advantage of our approach is that we define a structure by decomposing it as a collection of 'building stones' which we call structure blocks. This allows us to state the results in their natural, most general context.