2015 年 7 巻 p. 37-40
In this article, we deal with the iterative methods for solving unsymmetric linear systems, especially BiCGSTAB. The introduced parameter in BiCGSTAB at each iteration is selected to minimize the 2-norm of the residual vector. Here, we suggest another way to select the parameter by the idea of weighting used in Weighted GMRES. By our procedure, more importance is assigned to the larger entry of the residual vector so that faster convergence can be expected. In numerical experiments, it is shown that our procedure is efficient compared with the original BiCGSTAB.