! ! ! 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_d_dec_aggregator_mod use amg_d_base_aggregator_mod !> \namespace amg_d_dec_aggregator_mod \class amg_d_dec_aggregator_type !! \extends amg_d_base_aggregator_mod::amg_d_base_aggregator_type !! !! type, extends(amg_d_base_aggregator_type) :: amg_d_dec_aggregator_type !! procedure(amg_d_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_d_base_aggregator_type) :: amg_d_dec_aggregator_type procedure(amg_d_soc_map_bld), nopass, pointer :: soc_map_bld => null() contains procedure, pass(ag) :: bld_tprol => amg_d_dec_aggregator_build_tprol procedure, pass(ag) :: mat_bld => amg_d_dec_aggregator_mat_bld procedure, pass(ag) :: mat_asb => amg_d_dec_aggregator_mat_asb procedure, pass(ag) :: default => amg_d_dec_aggregator_default procedure, pass(ag) :: set_aggr_type => amg_d_dec_aggregator_set_aggr_type procedure, pass(ag) :: descr => amg_d_dec_aggregator_descr procedure, nopass :: fmt => amg_d_dec_aggregator_fmt end type amg_d_dec_aggregator_type procedure(amg_d_soc_map_bld) :: amg_d_soc1_map_bld, amg_d_soc2_map_bld interface subroutine amg_d_dec_aggregator_build_tprol(ag,parms,ag_data,& & a,desc_a,ilaggr,nlaggr,t_prol,info) import :: amg_d_dec_aggregator_type, psb_desc_type, psb_dspmat_type, psb_dpk_, & & psb_ipk_, psb_lpk_, psb_ldspmat_type, amg_dml_parms, amg_daggr_data implicit none class(amg_d_dec_aggregator_type), target, intent(inout) :: ag type(amg_dml_parms), intent(inout) :: parms type(amg_daggr_data), intent(in) :: ag_data type(psb_dspmat_type), intent(inout) :: a type(psb_desc_type), intent(inout) :: desc_a integer(psb_lpk_), allocatable, intent(out) :: ilaggr(:),nlaggr(:) type(psb_ldspmat_type), intent(out) :: t_prol integer(psb_ipk_), intent(out) :: info end subroutine amg_d_dec_aggregator_build_tprol end interface interface subroutine amg_d_dec_aggregator_mat_bld(ag,parms,a,desc_a,ilaggr,nlaggr,& & ac,desc_ac,op_prol,op_restr,t_prol,info) import :: amg_d_dec_aggregator_type, psb_desc_type, psb_dspmat_type, psb_dpk_, & & psb_ipk_, psb_lpk_, psb_ldspmat_type, amg_dml_parms implicit none class(amg_d_dec_aggregator_type), target, intent(inout) :: ag type(amg_dml_parms), intent(inout) :: parms type(psb_dspmat_type), intent(in) :: a type(psb_desc_type), intent(inout) :: desc_a integer(psb_lpk_), intent(inout) :: ilaggr(:), nlaggr(:) type(psb_ldspmat_type), intent(inout) :: t_prol type(psb_dspmat_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_d_dec_aggregator_mat_bld end interface interface subroutine amg_d_dec_aggregator_mat_asb(ag,parms,a,desc_a,& & ac,desc_ac,op_prol,op_restr,info) import :: amg_d_dec_aggregator_type, psb_desc_type, psb_dspmat_type, psb_dpk_, & & psb_ipk_, psb_lpk_, psb_ldspmat_type, amg_dml_parms implicit none class(amg_d_dec_aggregator_type), target, intent(inout) :: ag type(amg_dml_parms), intent(inout) :: parms type(psb_dspmat_type), intent(in) :: a type(psb_desc_type), intent(inout) :: desc_a type(psb_dspmat_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_d_dec_aggregator_mat_asb end interface contains subroutine amg_d_dec_aggregator_set_aggr_type(ag,parms,info) use amg_base_prec_type implicit none class(amg_d_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_d_soc1_map_bld case (amg_soc2_) ag%soc_map_bld => amg_d_soc2_map_bld case default write(0,*) 'Unknown aggregation type, defaulting to SOC1' ag%soc_map_bld => amg_d_soc1_map_bld end select return end subroutine amg_d_dec_aggregator_set_aggr_type subroutine amg_d_dec_aggregator_default(ag) implicit none class(amg_d_dec_aggregator_type), intent(inout) :: ag call ag%amg_d_base_aggregator_type%default() ag%soc_map_bld => amg_d_soc1_map_bld return end subroutine amg_d_dec_aggregator_default function amg_d_dec_aggregator_fmt() result(val) implicit none character(len=32) :: val val = "Decoupled aggregation" end function amg_d_dec_aggregator_fmt subroutine amg_d_dec_aggregator_descr(ag,parms,iout,info,prefix) implicit none class(amg_d_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_d_dec_aggregator_descr end module amg_d_dec_aggregator_mod