There are many preconditioners for linear systems, for example, P = I + Smax developed by Kotakemori in [9] and its extension P˜ developed by Arenas & Yong in [1]. These preconditioners were built to speed up the convergence ...

The class of Z-matrices is the set of matrices whose off-diagonal entries are non positive. Solving a linear system of the form Ax = b is possible if the coefficient matrix A has certain characteristics such as being of ...