In this chapter we study iterative methods, derived from those of Chapter 8, that do not need a multiplication with the transpose of A. They are sometimes called product-type or transpose-free methods. We consider, particularly, CGS and BiCGStab and their variants....
We investigate several variants how to solve these tridiagonal systems, the Thomas algorithm, the Thomas combined with the SPIKE algorithm, and a polynomial approximation of the inverse. We test the various implementations numerically by means of two- and three-dimensional examples. It turns out ...