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amg4psblas/amgprec/amg_z_dec_aggregator_mod.f90

209 lines
8.7 KiB
Fortran

!
!
! AMG4PSBLAS version 1.0
! Algebraic Multigrid Package
! based on PSBLAS (Parallel Sparse BLAS version 3.7)
!
! (C) Copyright 2021
!
! Salvatore Filippone
! Pasqua D'Ambra
! Fabio Durastante
!
! Redistribution and use in source and binary forms, with or without
! modification, are permitted provided that the following conditions
! are met:
! 1. Redistributions of source code must retain the above copyright
! notice, this list of conditions and the following disclaimer.
! 2. Redistributions in binary form must reproduce the above copyright
! notice, this list of conditions, and the following disclaimer in the
! documentation and/or other materials provided with the distribution.
! 3. The name of the AMG4PSBLAS group or the names of its contributors may
! not be used to endorse or promote products derived from this
! software without specific written permission.
!
! THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
! ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
! TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
! PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AMG4PSBLAS GROUP OR ITS CONTRIBUTORS
! BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
! CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
! SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
! INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
! CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
! ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
! POSSIBILITY OF SUCH DAMAGE.
!
! Basic (decoupled) aggregation algorithm. Based on the ideas in
! M. Brezina and P. Vanek, A black-box iterative solver based on a
! two-level Schwarz method, Computing, 63 (1999), 233-263.
! P. Vanek, J. Mandel and M. Brezina, Algebraic Multigrid by Smoothed
! Aggregation for Second and Fourth Order Elliptic Problems, Computing, 56
! (1996), 179-196.
!
module amg_z_dec_aggregator_mod
use amg_z_base_aggregator_mod
!> \namespace amg_z_dec_aggregator_mod \class amg_z_dec_aggregator_type
!! \extends amg_z_base_aggregator_mod::amg_z_base_aggregator_type
!!
!! type, extends(amg_z_base_aggregator_type) :: amg_z_dec_aggregator_type
!! procedure(amg_z_soc_map_bld), nopass, pointer :: soc_map_bld => null()
!! end type
!!
!! This is the simplest aggregation method: starting from the
!! strength-of-connection measure for defining the aggregation
!! presented in
!!
!! M. Brezina and P. Vanek, A black-box iterative solver based on a
!! two-level Schwarz method, Computing, 63 (1999), 233-263.
!! P. Vanek, J. Mandel and M. Brezina, Algebraic Multigrid by Smoothed
!! Aggregation for Second and Fourth Order Elliptic Problems, Computing, 56
!! (1996), 179-196.
!!
!! it achieves parallelization by simply acting on the local matrix,
!! i.e. by "decoupling" the subdomains.
!! The data structure hosts a "map_bld" function pointer which allows to
!! choose other ways to measure "strength-of-connection", of which the
!! Vanek-Brezina-Mandel is the default. More details are available in
!!
!! P. D'Ambra, D. di Serafino and S. Filippone, On the development of
!! PSBLAS-based parallel two-level Schwarz preconditioners, Appl. Num. Math.
!! 57 (2007), 1181-1196.
!!
!! The soc_map_bld method is used inside the implementation of build_tprol
!!
!
!
type, extends(amg_z_base_aggregator_type) :: amg_z_dec_aggregator_type
procedure(amg_z_soc_map_bld), nopass, pointer :: soc_map_bld => null()
contains
procedure, pass(ag) :: bld_tprol => amg_z_dec_aggregator_build_tprol
procedure, pass(ag) :: mat_bld => amg_z_dec_aggregator_mat_bld
procedure, pass(ag) :: mat_asb => amg_z_dec_aggregator_mat_asb
procedure, pass(ag) :: default => amg_z_dec_aggregator_default
procedure, pass(ag) :: set_aggr_type => amg_z_dec_aggregator_set_aggr_type
procedure, pass(ag) :: descr => amg_z_dec_aggregator_descr
procedure, nopass :: fmt => amg_z_dec_aggregator_fmt
end type amg_z_dec_aggregator_type
procedure(amg_z_soc_map_bld) :: amg_z_soc1_map_bld, amg_z_soc2_map_bld
interface
subroutine amg_z_dec_aggregator_build_tprol(ag,parms,ag_data,&
& a,desc_a,ilaggr,nlaggr,t_prol,info)
import :: amg_z_dec_aggregator_type, psb_desc_type, psb_zspmat_type, psb_dpk_, &
& psb_ipk_, psb_lpk_, psb_lzspmat_type, amg_dml_parms, amg_daggr_data
implicit none
class(amg_z_dec_aggregator_type), target, intent(inout) :: ag
type(amg_dml_parms), intent(inout) :: parms
type(amg_daggr_data), intent(in) :: ag_data
type(psb_zspmat_type), intent(inout) :: a
type(psb_desc_type), intent(inout) :: desc_a
integer(psb_lpk_), allocatable, intent(out) :: ilaggr(:),nlaggr(:)
type(psb_lzspmat_type), intent(out) :: t_prol
integer(psb_ipk_), intent(out) :: info
end subroutine amg_z_dec_aggregator_build_tprol
end interface
interface
subroutine amg_z_dec_aggregator_mat_bld(ag,parms,a,desc_a,ilaggr,nlaggr,&
& ac,desc_ac,op_prol,op_restr,t_prol,info)
import :: amg_z_dec_aggregator_type, psb_desc_type, psb_zspmat_type, psb_dpk_, &
& psb_ipk_, psb_lpk_, psb_lzspmat_type, amg_dml_parms
implicit none
class(amg_z_dec_aggregator_type), target, intent(inout) :: ag
type(amg_dml_parms), intent(inout) :: parms
type(psb_zspmat_type), intent(in) :: a
type(psb_desc_type), intent(inout) :: desc_a
integer(psb_lpk_), intent(inout) :: ilaggr(:), nlaggr(:)
type(psb_lzspmat_type), intent(inout) :: t_prol
type(psb_zspmat_type), intent(out) :: op_prol, ac,op_restr
type(psb_desc_type), intent(inout) :: desc_ac
integer(psb_ipk_), intent(out) :: info
end subroutine amg_z_dec_aggregator_mat_bld
end interface
interface
subroutine amg_z_dec_aggregator_mat_asb(ag,parms,a,desc_a,&
& ac,desc_ac,op_prol,op_restr,info)
import :: amg_z_dec_aggregator_type, psb_desc_type, psb_zspmat_type, psb_dpk_, &
& psb_ipk_, psb_lpk_, psb_lzspmat_type, amg_dml_parms
implicit none
class(amg_z_dec_aggregator_type), target, intent(inout) :: ag
type(amg_dml_parms), intent(inout) :: parms
type(psb_zspmat_type), intent(in) :: a
type(psb_desc_type), intent(inout) :: desc_a
type(psb_zspmat_type), intent(inout) :: op_prol,ac,op_restr
type(psb_desc_type), intent(inout) :: desc_ac
integer(psb_ipk_), intent(out) :: info
end subroutine amg_z_dec_aggregator_mat_asb
end interface
contains
subroutine amg_z_dec_aggregator_set_aggr_type(ag,parms,info)
use amg_base_prec_type
implicit none
class(amg_z_dec_aggregator_type), intent(inout) :: ag
type(amg_dml_parms), intent(in) :: parms
integer(psb_ipk_), intent(out) :: info
select case(parms%aggr_type)
case (amg_noalg_)
ag%soc_map_bld => null()
case (amg_soc1_)
ag%soc_map_bld => amg_z_soc1_map_bld
case (amg_soc2_)
ag%soc_map_bld => amg_z_soc2_map_bld
case default
write(0,*) 'Unknown aggregation type, defaulting to SOC1'
ag%soc_map_bld => amg_z_soc1_map_bld
end select
return
end subroutine amg_z_dec_aggregator_set_aggr_type
subroutine amg_z_dec_aggregator_default(ag)
implicit none
class(amg_z_dec_aggregator_type), intent(inout) :: ag
call ag%amg_z_base_aggregator_type%default()
ag%soc_map_bld => amg_z_soc1_map_bld
return
end subroutine amg_z_dec_aggregator_default
function amg_z_dec_aggregator_fmt() result(val)
implicit none
character(len=32) :: val
val = "Decoupled aggregation"
end function amg_z_dec_aggregator_fmt
subroutine amg_z_dec_aggregator_descr(ag,parms,iout,info,prefix)
implicit none
class(amg_z_dec_aggregator_type), intent(in) :: ag
type(amg_dml_parms), intent(in) :: parms
integer(psb_ipk_), intent(in) :: iout
integer(psb_ipk_), intent(out) :: info
character(len=*), intent(in), optional :: prefix
character(1024) :: prefix_
if (present(prefix)) then
prefix_ = prefix
else
prefix_ = ""
end if
write(iout,*) trim(prefix_),' ','Decoupled Aggregator'
write(iout,*) trim(prefix_),' ','Aggregator object type: ',ag%fmt()
call parms%mldescr(iout,info,prefix=prefix)
return
end subroutine amg_z_dec_aggregator_descr
end module amg_z_dec_aggregator_mod