Parameter dependent quasiseparable systemsFast solution of shifted linear systems, with applications to matrix equations with quasiseparable coefficients and to the computation of functions of quasiseparable matrices. This is companion software to the manuscript Efficient Solution of Parameter Dependent Quasiseparable Systems (with Y. Eidelman and L. Gemignani).
Structured QR/QZCode for fast computation of eigenvalues of companion matrices using a structured version of the implicit QR method.
Without compression:This is a Fortran 90 implementation of the algorithms described in the paper A Fast Implicit QR Eigenvalue Algorithm for Companion Matrices (with D. A. Bini, Y. Eidelman, L. Gemignani and I. Gohberg, LAA 2010).
With compression:Companion software to the article Implicit QR with Compression (with Y. Eidelman, L. Gemignani and I. Gohberg, Indag. Math. 2012).
Structured QZ for companion pencilsCode for fast computation of generalized eigenvalues of companion pencils. The single-shift version is companion software to the article Implicit QR for companion-like pencils (with Y. Eidelman and L. Gemignani, Math. Comp. 2016). The double-shift version implements the algorithm described in the preprint A real QZ algorithm for structured companion pencils (with Y. Eidelman and L. Gemignani, 2016).
Approximate polynomial GCDMatlab code for fast computation of approximate polynomial GCD. This is an implementation of the fast algorithm described in the paper
A fast algorithm for approximate polynomial gcd based on structured matrix computations (with D.A. Bini, Operator Theory 2010).
Multiplication Matrix GCDMatlab code for fast implementation of approximate polynomial GCD with one exact polynomial. Companion software to the paper Extended companion matrix for approximate GCD (with O. Ruatta), presented at SNC 2011.