call p%apply(x,y,desc_a,info [,trans,work])

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 a Krylov solver from
PSBLAS, p%apply is called within the PSBLAS method psb_krylov and hence it is
completely transparent to the user.

Arguments

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 |

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. |