关键词：特征问题；兰索斯分块法；迭代
摘 要：In this paper, we demonstrate that bounds on accuracy for the finite precision Lanczos method given by Paige [\emph{Lin. Alg. Appl.}, 34:235--258, 1980] can be extended to the $s$-step Lanczos case assuming a bound on the condition numbers of the computed $s$-step bases. Our results confirm theoretically what is well-known empirically: the conditioning of the Krylov bases plays a large role in determining finite precision behavior.