Use of the multigrid methods for heat radiation problem.
Using FGMRES to obtain backward stability in mixed precision.
Using successive approximations for improving the convergence of GMRES method
In this paper, our attention is concentrated on the GMRES method for the solution of the system of linear algebraic equations with a nonsymmetric matrix. We perform pre-iterations before starting GMRES and put for the initial approximation in GMRES. We derive an upper estimate for the norm of the error vector in dependence on the th powers of eigenvalues of the matrix . Further we study under what eigenvalues lay-out this upper estimate is the best one. The estimate shows and numerical...