! ! ! MLD2P4 version 2.1 ! MultiLevel Domain Decomposition Parallel Preconditioners Package ! based on PSBLAS (Parallel Sparse BLAS version 3.5) ! ! (C) Copyright 2008, 2010, 2012, 2015, 2017 , 2017 ! ! Salvatore Filippone Cranfield University ! Ambra Abdullahi Hassan University of Rome Tor Vergata ! Pasqua D'Ambra IAC-CNR, Naples, IT ! Daniela di Serafino University of Campania "L. Vanvitelli", Caserta, IT ! ! 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 MLD2P4 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 MLD2P4 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. ! ! ! File: mld_d_base_aggregator_mat_asb.f90 ! ! Subroutine: mld_d_base_aggregator_mat_asb ! Version: real ! ! This routine builds the matrix associated to the current level of the ! multilevel preconditioner from the matrix associated to the previous level, ! by using the user-specified aggregation technique (therefore, it also builds the ! prolongation and restriction operators mapping the current level to the ! previous one and vice versa). ! The current level is regarded as the coarse one, while the previous as ! the fine one. This is in agreement with the fact that the routine is called, ! by mld_mlprec_bld, only on levels >=2. ! The coarse-level matrix A_C is built from a fine-level matrix A ! by using the Galerkin approach, i.e. ! ! A_C = P_C^T A P_C, ! ! where P_C is a prolongator from the coarse level to the fine one. ! ! A mapping from the nodes of the adjacency graph of A to the nodes of the ! adjacency graph of A_C has been computed by the mld_aggrmap_bld subroutine. ! The prolongator P_C is built here from this mapping, according to the ! value of p%iprcparm(mld_aggr_kind_), specified by the user through ! mld_dprecinit and mld_zprecset. ! On output from this routine the entries of AC, op_prol, op_restr ! are still in "global numbering" mode; this is fixed in the calling routine ! mld_d_lev_aggrmat_asb. ! ! Currently four different prolongators are implemented, corresponding to ! four aggregation algorithms: ! 1. un-smoothed aggregation, ! 2. smoothed aggregation, ! 3. "bizarre" aggregation. ! 4. minimum energy ! 1. The non-smoothed aggregation uses as prolongator the piecewise constant ! interpolation operator corresponding to the fine-to-coarse level mapping built ! by p%aggr%bld_tprol. This is called tentative prolongator. ! 2. The smoothed aggregation uses as prolongator the operator obtained by applying ! a damped Jacobi smoother to the tentative prolongator. ! 3. The "bizarre" aggregation uses a prolongator proposed by the authors of MLD2P4. ! This prolongator still requires a deep analysis and testing and its use is ! not recommended. ! 4. Minimum energy aggregation ! ! For more details see ! M. Brezina and P. Vanek, A black-box iterative solver based on a two-level ! Schwarz method, Computing, 63 (1999), 233-263. ! 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. ! M. Sala, R. Tuminaro: A new Petrov-Galerkin smoothed aggregation preconditioner ! for nonsymmetric linear systems, SIAM J. Sci. Comput., 31(1):143-166 (2008) ! ! ! The main structure is: ! 1. Perform sanity checks; ! 2. Compute prolongator/restrictor/AC ! ! ! Arguments: ! ag - type(mld_d_base_aggregator_type), input/output. ! The aggregator object ! parms - type(mld_dml_parms), input ! The aggregation parameters ! a - type(psb_dspmat_type), input. ! The sparse matrix structure containing the local part of ! the fine-level matrix. ! desc_a - type(psb_desc_type), input. ! The communication descriptor of the fine-level matrix. ! The 'one-level' data structure that will contain the local ! part of the matrix to be built as well as the information ! concerning the prolongator and its transpose. ! ilaggr - integer, dimension(:), input ! The mapping between the row indices of the coarse-level ! matrix and the row indices of the fine-level matrix. ! ilaggr(i)=j means that node i in the adjacency graph ! of the fine-level matrix is mapped onto node j in the ! adjacency graph of the coarse-level matrix. Note that the indices ! are assumed to be shifted so as to make sure the ranges on ! the various processes do not overlap. ! nlaggr - integer, dimension(:) input ! nlaggr(i) contains the aggregates held by process i. ! ac - type(psb_dspmat_type), output ! The coarse matrix on output ! ! op_prol - type(psb_dspmat_type), input/output ! The tentative prolongator on input, the computed prolongator on output ! ! op_restr - type(psb_dspmat_type), output ! The restrictor operator; normally, it is the transpose of the prolongator. ! ! info - integer, output. ! Error code. ! subroutine mld_d_bcmatch_aggregator_mat_asb(ag,parms,a,desc_a,ilaggr,nlaggr,ac,op_prol,op_restr,info) use psb_base_mod use mld_d_inner_mod use mld_d_prec_type use mld_d_bcmatch_aggregator_mod, mld_protect_name => mld_d_bcmatch_aggregator_mat_asb implicit none class(mld_d_bcmatch_aggregator_type), target, intent(inout) :: ag type(mld_dml_parms), intent(inout) :: parms type(psb_dspmat_type), intent(in) :: a type(psb_desc_type), intent(in) :: desc_a integer(psb_ipk_), intent(inout) :: ilaggr(:), nlaggr(:) type(psb_dspmat_type), intent(inout) :: op_prol type(psb_dspmat_type), intent(out) :: ac,op_restr integer(psb_ipk_), intent(out) :: info ! Local variables character(len=20) :: name integer(psb_mpk_) :: ictxt, np, me type(psb_d_coo_sparse_mat) :: acoo, bcoo type(psb_d_csr_sparse_mat) :: acsr1 integer(psb_ipk_) :: nzl,ntaggr integer(psb_ipk_) :: err_act integer(psb_ipk_) :: debug_level, debug_unit name='mld_d_bcmatch_aggregator_mat_asb' if (psb_get_errstatus().ne.0) return call psb_erractionsave(err_act) debug_unit = psb_get_debug_unit() debug_level = psb_get_debug_level() info = psb_success_ ictxt = desc_a%get_context() call psb_info(ictxt,me,np) ! ! Build the coarse-level matrix from the fine-level one, starting from ! the mapping defined by mld_aggrmap_bld and applying the aggregation ! algorithm specified by ! select case (parms%aggr_prol) case (mld_no_smooth_) call mld_daggrmat_unsmth_spmm_asb(a,desc_a,ilaggr,nlaggr,& & parms,ac,op_prol,op_restr,info) case(mld_smooth_prol_) call mld_daggrmat_smth_asb(a,desc_a,ilaggr,nlaggr, & & parms,ac,op_prol,op_restr,info) case(mld_biz_prol_) call mld_daggrmat_biz_asb(a,desc_a,ilaggr,nlaggr, & & parms,ac,op_prol,op_restr,info) case(mld_min_energy_) call mld_daggrmat_minnrg_asb(a,desc_a,ilaggr,nlaggr, & & parms,ac,op_prol,op_restr,info) case default info = psb_err_internal_error_ call psb_errpush(info,name,a_err='Invalid aggr kind') goto 9999 end select if (info /= psb_success_) then call psb_errpush(psb_err_from_subroutine_,name,a_err='Inner aggrmat asb') goto 9999 end if call psb_erractionrestore(err_act) return 9999 call psb_error_handler(err_act) return end subroutine mld_d_bcmatch_aggregator_mat_asb