Abstract
The class of eigenvalue problems for upper Hessenberg matrices of banded-plus-spike form includes companion and comrade matrices as special cases. For this class of matrices a factored form is developed in which the matrix is represented as a product of essentially 2×2 matrices and a banded upper-triangular matrix. A non-unitary analogue of Francis’s implicitly-shifted QR algorithm that preserves the factored form and consequently computes the eigenvalues in O(n 2) time and O(n) space is developed. Inexpensive a posteriori tests for stability and accuracy are performed as part of the algorithm. The results of numerical experiments are mixed but promising in certain areas. The single-shift version of the code applied to companion matrices is much faster than the nearest competitor.
Similar content being viewed by others
References
Aurentz, J.L., Vandebril, R., Watkins, D.S.: Fast computation of the zeros of a polynomial via factorization of the companion matrix. SIAM J. Sci. Comput. 35, A255–A269 (2013)
Barnett, S.: Polynomials and Linear Control Systems. Dekker, New York (1983)
Bini, D.A., Eidelman, Y., Gemignani, L., Gohberg, I.: Fast QR eigenvalue algorithms for Hessenberg matrices which are rank-one perturbations of unitary matrices. SIAM J. Matrix Anal. Appl. 29, 566–585 (2007)
Bini, D.A., Boito, P., Eidelman, Y., Gemignani, L., Gohberg, I.: A fast implicit QR algorithm for companion matrices. Linear Algebra Appl. 432, 2006–2031 (2010)
Boito, P., Eidelman, Y., Gemignani, L., Gohberg, I.: Implicit QR with compression. Indag. Math. 23, 733–761 (2012)
Chandrasekaran, S., Gu, M., Xia, J., Zhu, J.: A fast QR algorithm for companion matrices. Oper. Theory, Adv. Appl. 179, 111–143 (2007)
Eidelman, Y., Gemignani, L., Gohberg, I.: Efficient eigenvalue computation for quasiseparable Hermitian matrices under low rank perturbation. Numer. Algorithms 47, 253–273 (2008)
Fernando, K.V., Parlett, B.N.: Accurate singular values and differential qd algorithms. Numer. Math. 67, 191–229 (1994)
Fiedler, M.: A note on companion matrices. Linear Algebra Appl. 372, 325–331 (2003)
Francis, J.G.F.: The QR transformation, part II. Comput. J. 4, 332–345 (1962)
Good, I.J.: The colleague matrix, a Chebyshev analogue of the companion matrix. Q. J. Math. 12, 61–68 (1961)
Parlett, B.N.: The new qd algorithms. Acta Numer. 4, 459–491 (1995)
Van Barel, M., Vandebril, R., Van Dooren, P., Frederix, K.: Implicit double shift QR-algorithm for companion matrices. Numer. Math. 116, 177–212 (2010)
Vandebril, R., Del Corso, G.M.: An implicit multishift QR-algorithm for Hermitian plus low rank matrices. SIAM J. Sci. Comput. 32, 2190–2212 (2010)
Vandebril, R., Van Barel, M., Mastronardi, N.: Matrix Computations and Semiseparable Matrices, Vol. II: Eigenvalue and Singular Value Methods. Johns Hopkins University Press, Baltimore (2008)
Watkins, D.S.: The Matrix Eigenvalue Problem: GR and Krylov Subspace Methods. SIAM, Philadelphia (2007)
Watkins, D.S.: Fundamentals of Matrix Computations, 3rd edn. Wiley, New York (2010)
Watkins, D.S.: Francis’s algorithm. Am. Math. Mon. 118(5), 387–403 (2011)
Zhlobich, P.: Differential qd algorithm with shifts for rank-structured matrices. SIAM J. Matrix Anal. Appl. 33, 1153–1171 (2012)
Author information
Authors and Affiliations
Corresponding author
Additional information
Communicated by Peter Benner.
The research was partially supported by the Research Council KU Leuven, projects OT/11/055 (Spectral Properties of Perturbed Normal Matrices and their Applications), CoE EF/05/006 Optimization in Engineering (OPTEC), by the Fund for Scientific Research–Flanders (Belgium) project G034212N (Reestablishing smoothness for matrix manifold optimization via resolution of singularities) and by the Interuniversity Attraction Poles Programme, initiated by the Belgian State, Science Policy Office, Belgian Network DYSCO (Dynamical Systems, Control, and Optimization).
Rights and permissions
About this article
Cite this article
Aurentz, J.L., Vandebril, R. & Watkins, D.S. Fast computation of eigenvalues of companion, comrade, and related matrices. Bit Numer Math 54, 7–30 (2014). https://doi.org/10.1007/s10543-013-0449-x
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10543-013-0449-x