Abstract
We present a transpose-free version of the nonsymmetric scaled Lanczos procedure. It generates the same tridiagonal matrix as the classical algorithm, using two matrix-vector products per iteration without accessing AT. We apply this algorithm to obtain a transpose-free version of the Quasi-minimal residual method of Freund and Nachtigal [15] (without look-ahead), which requires three matrix-vector products per iteration. We also present a related transpose-free version of the bi-conjugate gradients algorithm.
Original language | English (US) |
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Pages (from-to) | 51-66 |
Number of pages | 16 |
Journal | Numerical Algorithms |
Volume | 17 |
Issue number | 1-2 |
DOIs | |
State | Published - 1998 |
Externally published | Yes |
Keywords
- Bi-conjugate gradients algorithm
- Krylov subspace methods
- Lanczos algorithm
- Nonsymmetric linear systems
- Quasi-minimal residual algorithm
ASJC Scopus subject areas
- Applied Mathematics