Subroutine mld_precinit

mld_precinit(p,ptype,info)
mld_precinit(p,ptype,info,nlev)

This routine allocates and initializes the preconditioner data structure, according to the preconditioner type chosen by the user.

Arguments

p	type(mld_xprec_type), intent(inout).
	The preconditioner data structure. Note that x must be chosen according to the real/complex, single/double precision version of MLD2P4 under use.
ptype	character(len=*), intent(in).
	The type of preconditioner (see below).
	Note that the strings are case insensitive.
info	integer, intent(out).
	Error code. If no error, 0 is returned. See Section 7 for details.
nlev	integer, optional, intent(in).
	The number of levels of the multilevel preconditioner. If nlev is not present and ptype='ML', 'ml', then nlev=2 is assumed. Otherwise, nlev is ignored.

The available preconditioner types are those described in table 1, briefly repeated here: Legal inputs to this subroutine are interpreted depending on the $ptype$ string as follows¹:

NOPREC

No Preconditioner

JACOBI

Point-Jacobi (the string DIAG is also allowed);

BJAC

Block-Jacobi;

AS

Additive Schwarz;

ML

Multi-Level Schwarz.