2010/04/27 by Joseph F. Grcar, Grcar, Joseph F.
Engineering · Mathematics · #65F35 #Advanced Control Systems Optimization #Advanced Optimization Algorithms Research #FOS: Mathematics #Iterative Learning Control Systems #Numerical Analysis (math.NA) #Primary 65F20 #Secondary 15A63
paper · pdf · doi:10.48550/arxiv.1004.4921
openalex publication_date 2010/04/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Contrary to an assumption made by Bojanczyk, Higham, and Patel [SIAM J. Matrix Anal. Appl., 24(4):914-931, 2003], a perturbation bound for indefinite least square problems is capable of arbitrarily large overestimates for all perturbations of some problems. For these problems, the hyperbolic QR factorization algorithm is not proved to be forward stable because the error bound systematically overestimates the solution error of backward stable methods.