BTTB preconditioners for BTTB systems

  • Authors:
  • Fu-Rong Lin;Chi-Xi Wang

  • Affiliations:
  • Department of Mathematics, Shantou University, Guangdong, People's Republic of China 515063;Department of Information and Electronic Engineering, Xuzhou College of Industrial Technology, Jiangsu, People's Republic of China 221006

  • Venue:
  • Numerical Algorithms
  • Year:
  • 2012

Quantified Score

Hi-index 0.00

Visualization

Abstract

In this paper, we consider solving the BTTB system ${\cal T}_{m,n}[f] {\bf{x}} = {\bf{b}}$ by the preconditioned conjugate gradient (PCG) method, where ${\cal T}_{m,n}[f]$ denotes the m 脳 m block Toeplitz matrix with n 脳 n Toeplitz blocks (BTTB) generated by a (2驴, 2驴)-periodic continuous function f(x, y). We propose using the BTTB matrix ${\cal T}_{m,n}[1/f]$ to precondition the BTTB system and prove that only O(m)驴+驴O(n) eigenvalues of the preconditioned matrix ${\cal T}_{m,n}[1/f] {\cal T}_{m,n}[f]$ are not around 1 under the condition that f(x, y)驴驴0. We then approximate 1/f(x, y) by a bivariate trigonometric polynomial, which can be obtained in O(m n log(m n)) operations by using the fast Fourier transform technique. Numerical results show that our BTTB preconditioner is more efficient than block circulant preconditioners.