5.8.1 Type-I preconditioner

We can choose the type-I preconditioner from Eq. (4.11b), (4.12a) and (4.13a). Especially the last is of interest.

Remark : All iteration methods introduced in Sec. 5.3 to 5.7 can be used as preconditioner in a CG (spd) or GMRES iteration. If the stiffness matrix is symmetric then the ASM-DD preconditioner [HLM91] using Schur complement preconditioners [BPS89,TCK92] fits exactly in the scheme of (4.12a).