Solutions of large-scale sparse linear algebraic systems are deeply involved in various scientific and engineering fields, such as computational electromagnetics, numerical solutions of high-order differential equations, optimization problems, fluid mechanics and reservoir modeling. Moreover, research of methods for solving large-scale sparse systems of linear algebraic equations becomes one of the key issues of large-scale scientific and engineering computing and such research has important theoretic significance and practical applications. In this paper, we study iteration methods to iterative solutions of large-scale sparse linear algebraic equations.Firstly, we give the generalized alternating two-stage method , then we study the convergence of the generalized alternating two-stage method when the coefficient matrix is a monotone matrix, a nonsingular H matrix, a symmetric positive definite matrix, respectively. Secondly, we study the convergence of the generalized alternating two-stage method when the coefficient matrix is an M - matrix with property c , a symmetric positive semi-definite matrix, respectively.Finally, we study the convergence of the GAOR method for solving the linear system Hy = ffor strictly doubly diagonally dominant andα-strictly doubly diagonally dominant coefficient matrices. We obtain bounds for the spectral radius of the matrix Lω,r which is the iterative matrix of the GAOR iterative method. Moreover, we present convergence theorems of the GAOR method and several numerical examples. |