Abstract
This paper considers the solutions of Hermitian Toeplitz systems where the Toeplitz matrices are generated by nonnegative functions ƒ. The preconditioned conjugate gradient method withwell-known circulant preconditioners fails in the case when ƒ has zeros. This paper employs Toeplitz matrices offixed bandwidth as preconditioners. Their generating functions g are trigonometric polynomials of fixed degree and aredetermined by minimizing the maximum relative error ||(ƒ - g)/ƒ||∞. Itis shown that the condition number of systems preconditioned by theband-Toeplitz matrices are O(1) for ƒ, with or withoutzeros. When ƒ is positive, the preconditioned systems converge at thesame rate as other well-known circulant preconditioned systems. An a prioribound of the number of iterations required for convergence is also given.
Original language | English |
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Pages (from-to) | 164-171 |
Number of pages | 8 |
Journal | SIAM Journal on Scientific Computing |
Volume | 15 |
Issue number | 1 |
DOIs | |
Publication status | Published - Jan 1994 |
Externally published | Yes |
Keywords
- Toeplitz matrix
- generating function
- preconditioned conjugate gradient method
- Chebyshev approximation
- Remez algorithm