Residual Smoothing Techniques for Iterative Methods
نویسندگان
چکیده
An iterative method for solving a linear system Ax b produces iterates {xk with associated residual norms that, in general, need not decrease "smoothly" to zero. "Residual smoothing" techniques are considered that generate a second sequence {Yk via a simple relation yk (1 0k)yk-+ r/kxk. The authors first review and comment on a technique of this form introduced by Sch6nauer and Weiss that results in {Yk} with monotone decreasing residual norms; this is referred to as minimal residual smoothing. Certain relationships between the residuals and residual norms of the biconjugate gradient (BCG) and quasi-minimal residual (QMR) methods are then noted, from which it follows that QMR can be obtained from BCG by a technique of this form; this technique is extended to generally applicable quasi-minimal residual smoothing. The practical performance of these techniques is illustrated in a number of numerical experiments.
منابع مشابه
VML : A Class of Virtual Multi - Level Iterative
We introduce virtual multi-level iterative methods (VML) which attempt to remove the low frequency errors by conducting some special smoothing (residual norm minimization) procedure with respect to the coarse grids. However, there is no coarse grid formed explicitly, no inter-grid transfer operator is needed, and even the smoothing procedure can be done almost locally. These properties are attr...
متن کاملMinimal Residual Smoothing in Multi-Level Iterative Method
A minimal residual smoothing (MRS) technique is employed to accelerate the convergence of the multi-level iterative method by smoothing the residuals of the original iterative sequence. The sequence with smoothed residuals is reintroduced into the multi-level iterative process. The new sequence generated by this acceleration procedure converges much faster than both the sequence generated by th...
متن کاملResidual Smoothing and Peak/plateau Behavior in Krylov Subspace Methods
Recent results on residual smoothing are reviewed, and it is observed that certain of these are equivalent to results obtained by different means that relate “peaks” and “plateaus” in residual norm sequences produced by certain pairs of Krylov subspace methods.
متن کاملPreconditioned Generalized Minimal Residual Method for Solving Fractional Advection-Diffusion Equation
Introduction Fractional differential equations (FDEs) have attracted much attention and have been widely used in the fields of finance, physics, image processing, and biology, etc. It is not always possible to find an analytical solution for such equations. The approximate solution or numerical scheme may be a good approach, particularly, the schemes in numerical linear algebra for solving ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- SIAM J. Scientific Computing
دوره 15 شماره
صفحات -
تاریخ انتشار 1994