Method apply

This method computes y = op(B^-1) x, where B is a previously built preconditioner, stored into p, and op denotes the preconditioner itself or its transpose, according to the value of trans. Note that, when AMG4PSBLAS is used with am iterative solver from PSBLAS, p%apply is called within the PSBLAS method psb_krylov and hence it is completely transparent to the user, who will almost never invoke it directly.

`x`	type`(kind_parameter)`, dimension(:), intent(in)—.
	The local part of the vector x. Note that type and kind_parameter must be chosen according to the `real`/`complex`, single/double precision version of AMG4PSBLAS under use.
`y`	type`(kind_parameter)`, dimension(:), intent(out)—.
	The local part of the vector y. Note that type and kind_parameter must be chosen according to the `real`/`complex`, single/double precision version of AMG4PSBLAS under use.
`desc_a`	`type(psb_desc_type), intent(in)`.
	The communication descriptor associated to the matrix to be preconditioned.
`info`	`integer, intent(out)`.
	Error code. If no error, 0 is returned. See Section 7 for details.
`trans`	`character(len=1), optional, intent(in).`
	If `trans` = `’N’,’n’` then op(B^-1) = B^-1; if `trans` = `’T’,’t’` then op(B^-1) = B^-T (transpose of B^-1); if `trans` = `’C’,’c’` then op(B^-1) = B^-C (conjugate transpose of B^-1).
`work`	type`(kind_parameter)`, dimension(:), optional, target—.
	Workspace. Its size should be at least `4 * psb_cd_get_local_` `cols(desc_a)` (see the PSBLAS User’s Guide). Note that type and kind_parameter must be chosen according to the `real`/`complex`, single/double precision version of AMG4PSBLAS under use.

5.6 Method apply