Improved initialization of the accelerated and robust QR-like polynomial root-finding.
Dario A. Bini, Luca Gemignani, Victor Ya. Pan · 2004
Abstract. We approximate polynomial roots numerically as the eigenvalues of a unitary diagonal plus rank-one matrix. We rely on our earlier adaptation of the ¤¦ ¥ algorithm, which exploits the semiseparable matrix structure to approximate the eigenvalues in a fast and robust way, but we substantially improve the performance of the resulting algorithm at the initial stage, as confirmed by our numerical tests.