FAST COMPUTATION OF THE ZEROS OF A POLYNOMIAL VIA FACTORIZATION OF THE COMPANION MATRIX

被引:18
作者
Aurentz, Jared L. [1 ]
Vandebril, Raf [2 ]
Watkins, David S. [1 ]
机构
[1] Washington State Univ, Dept Math, Pullman, WA 99164 USA
[2] Katholieke Univ Leuven, Dept Comp Sci, B-3001 Heverlee, Belgium
关键词
polynomial; root; companion matrix; QR algorithm; HESSENBERG MATRICES; ALGORITHMS;
D O I
10.1137/120865392
中图分类号
O29 [应用数学];
学科分类号
070104 ;
摘要
A new fast algorithm for computing the zeros of a polynomial in O(n(2)) time using O(n) memory is developed. The eigenvalues of the Frobenius companion matrix are computed by applying a nonunitary analogue of Francis's implicitly shifted QR algorithm to a factored form of the matrix. The algorithm achieves high speed and low memory use by preserving the factored form. It also provides a residual and an error estimate for each root. Numerical tests confirm the high speed of the algorithm.
引用
收藏
页码:A255 / A269
页数:15
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