OPERATOR TRIGONOMETRY OF ITERATIVE METHODS

A new and general approach to the understanding and analysis of widely used iterative methods for the numerical solution of the equation Ax = b is presented. This class of algorithms, which includes CGN, GMRES. ORTHOMIN, BCG, CGS, and others of current importance, utilizes residu al norm minimizing procedures, such as those often found under the gen eral names Galerkin method, Arnoldi method, Lanczos method, and so on. The view here is different: the needed error minimizations are seen t rigonometrically. (C) 1997 by John Wiley & Sons, Ltd.