Abstract
In this manuscript a new method will be presented for performing a QR-iteration with (A − σ I)(A − κ I)−1 = QR without explicit inversion of the factor (A − κ I)−1. A QR-method driven by a rational function is attractive since convergence can occur at both sides of the matrix. Each step of this new iteration consists of two substeps. In the explicit version, first an RQ-factorization of the initial matrix A − κ I = RQ will be computed, followed by a QR-factorization of the matrix (A − σ I)Q H. The factorization of (A − σ I)Q H can be computed in an intelligent manner, exploiting properties of the already known RQ-factorization of A − κ I. The similarity transformation yielding the QR-step is defined by the unitary factor Q in the QR-factorization of the transformed matrix (A − σ I)Q H. Examples will be given, illustrating how to efficiently compute the factorization for some specific classes of matrices. The novelties of this approach with respect to these matrix classes will be discussed.
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References
Wilkinson J.H.: The Algebraic Eigenvalue Problem. Numerical Mathematics and Scientific Computation. Oxford University Press, Oxford (1999)
Parlett, B.N.: The Symmetric Eigenvalue Problem. Classics in Applied Mathematics, vol. 20. SIAM, Philadelphia (1998)
Dubrulle A.A., Golub G.H.: A multishift QR iteration without computation of the shifts. Numer. Algorithms 7(2–4), 173–181 (1994)
Golub G.H., Van Loan C.F.: Matrix Computations, 3rd edn. The Johns Hopkins University Press, Baltimore (1996)
Watkins D.S., Elsner L.: Convergence of algorithms of decomposition type for the eigenvalue problem. Linear Algebra Appl. 143, 19–47 (1991)
Watkins D.S.: QR-like algorithms—an overview of convergence theory and practice. In: Renegar, J., Shub, M., Smale, S. (eds) The Mathematics of Numerical Analysis. Lectures in Applied Mathematics, vol. 32, pp. 879–893. American Mathematical Society, Providence (1996)
Ruhe A.: Rational Krylov sequence methods for eigenvalue computation. Linear Algebra Appl. 58, 391–405 (1984)
Ruhe A.: Rational krylov algorithms for nonsymmetric eigenvalue problems, II: Matrix pairs. Linear Algebra Appl. 197/198, 283–296 (1994)
Ruhe A.: The rational Krylov algorithm for nonsymmetric eigenvalue problems. III: Complex shifts for real matrices. BIT 34, 165–176 (1994)
Fasino D.: Rational Krylov matrices and QR-steps on Hermitian diagonal-plus-semiseparable matrices. Numer. Linear Algebra Appl. 12(8), 743–754 (2005)
Watkins D.S.: On the reduction of a Hamiltonian matrix to Hamiltonian Schur form. Electron. Trans. Numer. Anal. 23, 141–157 (2006)
Watkins D.S.: Bidirectional chasing algorithms for the eigenvalue problem. SIAM J. Matrix Anal. Appl. 14(1), 166–179 (1993)
Byers R.: A hamiltonian QR-algorithm. SIAM J. Sci. Stat. Comput. 7(1), 212–229 (1986)
Watkins D.S.: Bulge exchanges in algorithms of QR-type. SIAM J. Matrix Anal. Appl. 19(4), 1074–1096 (1998)
Wilkinson J.H.: The Algebraic Eigenvalue Problem. Oxford University Press, NY (1965)
Gantmacher, F.R., Kreĭ n, M.G.: Oscillation matrices and kernels and small vibrations of mechanical systems. AMS Chelsea Publishing, Providence, Rhode Island, revised edition (2002)
Vandebril R., Van Barel M., Mastronardi N.: An implicit QR-algorithm for symmetric semiseparable matrices. Numer. Linear Algebra Appl. 12(7), 625–658 (2005)
Eidelman Y., Gohberg I.C., Olshevsky V.: The QR iteration method for Hermitian quasiseparable matrices of an arbitrary order. Linear Algebra Appl. 404, 305–324 (2005)
Bini D.A., Daddi F., Gemignani L.: On the shifted QR iteration applied to companion matrices. Electron. Trans. Numer. Anal. 18, 137–152 (2004)
Bini D.A., Gemignani L., Pan V.Y.: Fast and stable QR eigenvalue algorithms for generalized companion matrices and secular equations. Numerische Mathematik 100(3), 373–408 (2005)
Bini D.A., Eidelman Y., Gemignani L., Gohberg I.C.: Fast QR eigenvalue algorithms for Hessenberg matrices which are rank-one perturbations of unitary matrices. SIAM J. Matrix Anal. Appl. 29(2), 566–585 (2007)
Watkins D.S.: Understanding the QR algorithm. SIAM Rev. 24(4), 427–440 (1982)
Vandebril, R., Van Barel, M., Mastronardi, N.: A new iteration for computing the eigenvalues of semiseparable (plus diagonal) matrices. Technical Report TW507, Department of Computer Science, Katholieke Universiteit Leuven, Celestijnenlaan 200A, 3000 Leuven (Heverlee), Belgium, October (2007)
Van Camp E., Mastronardi N., Van Barel M.: Two fast algorithms for solving diagonal-plus-semiseparable linear systems. J. Comput. Appl. Math. 164-165, 731–747 (2004)
Dewilde P., van der Veen A.-J.: Time-varying Systems and Computations. Kluwer, Boston (1998)
Eidelman Y., Gohberg I.C.: A modification of the Dewilde-van der Veen method for inversion of finite structured matrices. Linear Algebra Appl. 343-344, 419–450 (2002)
Vandebril, R., Van Barel, M., Mastronardi, N.: Matrix Computations and Semiseparable Matrices. Linear Systems, vol. I. The Johns Hopkins University Press, Baltimore (2008)
Delvaux S., Van Barel M.L.: A QR-based solver for rank structured matrices. SIAM J. Matrix Anal. Appl. 30(2), 464–490 (2008)
Van Barel M., Fasino D., Gemignani L., Mastronardi N.: Orthogonal rational functions and structured matrices. SIAM J. Matrix Anal. Appl. 26(3), 810–829 (2005)
Vandebril R., Van Camp E., Van Barel M., Mastronardi N.: On the convergence properties of the orthogonal similarity transformations to tridiagonal and semiseparable (plus diagonal) form. Numerische Mathematik 104, 205–239 (2006)
Wang Z.J., Wang T.L., Gragg W.B.: Convergence of the shifted QR algorithm, for unitary Hessenberg matrices. Math. Comput. 71(240), 1473–1496 (2002)
Wang Z.J., Wang T.L., : Convergence of the unitary QR algorithm with unimodular Wilkinson shift. Math. Comput. 72(241), 375–385 (2003)
Stewart, M.: Stability properties of several variants of the unitary Hessenberg QR-algorithm in structured matrices in mathematics. In: Computer Science and Engineering, II (Boulder, CO, 1999). Contemp. Math., vol. 281, pp. 57–72. Amer. Math. Soc., Providence (2001)
Gragg W.B.: The QR algorithm for unitary Hessenberg matrices. J. Comput. Appl. Math. 16, 1–8 (1986)
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The research of the authors R. Vandebril and M. Van Barel, was partially supported by the Research Council K.U.Leuven, project OT/05/40 (Large rank structured matrix computations), CoE EF/05/006 Optimization in Engineering (OPTEC), by the Fund for Scientific Research–Flanders (Belgium), G.0455.0 (RHPH: Riemann-Hilbert problems, random matrices and Padé-Hermite approximation), G.0423.05 (RAM: Rational modelling: optimal conditioning and stable algorithms), and by the Interuniversity Poles of Attraction Poles, initiated by the Belgian State, Science Policy Office, Belgian Network DYSCO (Dynamical Systems, Control, and Optimization). R. Vandebril has a grant as “Postdoctoraal Onderzoeker” from the Fund for Scientific Research–Flanders (Belgium). The work of N. Mastronardi was partially supported by MIUR, grant number 2004015437. The scientific responsibility rests with the authors.
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Vandebril, R., Van Barel, M. & Mastronardi, N. Rational QR-iteration without inversion. Numer. Math. 110, 561–575 (2008). https://doi.org/10.1007/s00211-008-0177-3
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DOI: https://doi.org/10.1007/s00211-008-0177-3