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amg4psblas/mlprec/impl/aggregator/amg_daggrmat_nosmth_bld.f90

199 lines
7.8 KiB
Fortran

!
!
! AMG4PSBLAS version 1.0
! Algebraic Multigrid Package
! based on PSBLAS (Parallel Sparse BLAS version 3.5)
!
! (C) Copyright 2020
!
! 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.
!
!
! File: amg_daggrmat_nosmth_bld.F90
!
! Subroutine: amg_daggrmat_nosmth_bld
! Version: real
!
! This routine builds a coarse-level matrix A_C 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 the piecewise constant interpolation operator corresponding
! the fine-to-coarse level mapping built by amg_aggrmap_bld.
!
! The coarse-level matrix A_C is distributed among the parallel processes or
! replicated on each of them, according to the value of p%parms%coarse_mat
! specified by the user through amg_dprecinit and amg_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
! aggregator%mat_bld.
!
! For details see
! 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.
!
!
! Arguments:
! 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.
! p - type(amg_d_onelev_type), input/output.
! 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.
! parms - type(amg_dml_parms), input
! Parameters controlling the choice of algorithm
! ac - type(psb_dspmat_type), output
! The coarse matrix on output
!
! 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.
! 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 amg_daggrmat_nosmth_bld(a,desc_a,ilaggr,nlaggr,parms,&
& ac,desc_ac,op_prol,op_restr,t_prol,info)
use psb_base_mod
use amg_base_prec_type
use amg_d_inner_mod, amg_protect_name => amg_daggrmat_nosmth_bld
use amg_d_base_aggregator_mod
implicit none
! Arguments
type(psb_dspmat_type), intent(in) :: a
type(psb_desc_type), intent(inout) :: desc_a
integer(psb_lpk_), intent(inout) :: ilaggr(:), nlaggr(:)
type(amg_dml_parms), intent(inout) :: parms
type(psb_dspmat_type), intent(inout) :: op_prol,ac,op_restr
type(psb_ldspmat_type), intent(inout) :: t_prol
type(psb_desc_type), intent(inout) :: desc_ac
integer(psb_ipk_), intent(out) :: info
! Local variables
integer(psb_ipk_) :: err_act
integer(psb_ipk_) :: ictxt, np, me, icomm, minfo
character(len=20) :: name
type(psb_ld_coo_sparse_mat) :: lcoo_prol
type(psb_d_coo_sparse_mat) :: coo_prol, coo_restr
type(psb_d_csr_sparse_mat) :: acsr
integer(psb_ipk_) :: debug_level, debug_unit
integer(psb_lpk_) :: nrow, nglob, ncol, ntaggr, nzl, ip, &
& naggr, nzt, naggrm1, naggrp1, i, k
integer(psb_ipk_) :: inaggr, nzlp
logical, parameter :: debug = .false.
name = 'amg_aggrmat_nosmth_bld'
info = psb_success_
call psb_erractionsave(err_act)
if (psb_errstatus_fatal()) then
info = psb_err_internal_error_; goto 9999
end if
ictxt = desc_a%get_context()
icomm = desc_a%get_mpic()
call psb_info(ictxt, me, np)
nglob = desc_a%get_global_rows()
nrow = desc_a%get_local_rows()
ncol = desc_a%get_local_cols()
naggr = nlaggr(me+1)
ntaggr = sum(nlaggr)
naggrm1 = sum(nlaggr(1:me))
naggrp1 = sum(nlaggr(1:me+1))
call a%cp_to(acsr)
call t_prol%mv_to(lcoo_prol)
inaggr = naggr
call psb_cdall(ictxt,desc_ac,info,nl=inaggr)
nzlp = lcoo_prol%get_nzeros()
call desc_ac%indxmap%g2lip_ins(lcoo_prol%ja(1:nzlp),info)
call lcoo_prol%set_ncols(desc_ac%get_local_cols())
call lcoo_prol%cp_to_icoo(coo_prol,info)
if (debug) call check_coo(me,trim(name)//' Check 1 on coo_prol:',coo_prol)
call psb_cdasb(desc_ac,info)
call psb_cd_reinit(desc_ac,info)
call amg_ptap_bld(acsr,desc_a,nlaggr,parms,ac,&
& coo_prol,desc_ac,coo_restr,info)
call coo_restr%set_nrows(desc_ac%get_local_rows())
call coo_restr%set_ncols(desc_a%get_local_cols())
call coo_prol%set_nrows(desc_a%get_local_rows())
call coo_prol%set_ncols(desc_ac%get_local_cols())
if (debug) call check_coo(me,trim(name)//' Check 1 on coo_restr:',coo_restr)
call op_prol%mv_from(coo_prol)
call op_restr%mv_from(coo_restr)
call psb_erractionrestore(err_act)
return
9999 call psb_error_handler(err_act)
return
contains
subroutine check_coo(me,string,coo)
implicit none
integer(psb_ipk_) :: me
type(psb_d_coo_sparse_mat) :: coo
character(len=*) :: string
integer(psb_lpk_) :: nr,nc,nz
nr = coo%get_nrows()
nc = coo%get_ncols()
nz = coo%get_nzeros()
write(0,*) me,string,nr,nc,&
& minval(coo%ia(1:nz)),maxval(coo%ia(1:nz)),&
& minval(coo%ja(1:nz)),maxval(coo%ja(1:nz))
end subroutine check_coo
end subroutine amg_daggrmat_nosmth_bld