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1156 lines
41 KiB
Fortran
1156 lines
41 KiB
Fortran
!!$
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!!$
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!!$ MLD2P4
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!!$ MultiLevel Domain Decomposition Parallel Preconditioners Package
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!!$ based on PSBLAS (Parallel Sparse BLAS v.2.0)
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!!$
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!!$ (C) Copyright 2007 Alfredo Buttari University of Rome Tor Vergata
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!!$ Pasqua D'Ambra ICAR-CNR, Naples
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!!$ Daniela di Serafino Second University of Naples
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!!$ Salvatore Filippone University of Rome Tor Vergata
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!!$
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!!$ Redistribution and use in source and binary forms, with or without
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!!$ modification, are permitted provided that the following conditions
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!!$ are met:
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!!$ 1. Redistributions of source code must retain the above copyright
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!!$ notice, this list of conditions and the following disclaimer.
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!!$ 2. Redistributions in binary form must reproduce the above copyright
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!!$ notice, this list of conditions, and the following disclaimer in the
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!!$ documentation and/or other materials provided with the distribution.
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!!$ 3. The name of the MLD2P4 group or the names of its contributors may
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!!$ not be used to endorse or promote products derived from this
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!!$ software without specific written permission.
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!!$
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!!$ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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!!$ ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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!!$ TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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!!$ PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE MLD2P4 GROUP OR ITS CONTRIBUTORS
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!!$ BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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!!$ CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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!!$ SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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!!$ INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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!!$ CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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!!$ ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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!!$ POSSIBILITY OF SUCH DAMAGE.
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!!$
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!!$
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! File: mld_zilut_fct.f90
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!
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! Subroutine: mld_zilut_fct
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! Version: real
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! Contains: mld_zilut_fctint, ilut_copyin, ilut_fact, ilut_copyout
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!
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! This routine computes the ILU(k,t) factorization of the local part of the
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! matrix stored into a. This factorization is used to build the 'base
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! preconditioner' (block-Jacobi preconditioner/solver, Additive Schwarz
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! preconditioner) corresponding to a certain level of a multilevel preconditioner.
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!
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! Details on the above factorization can be found in
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! Y. Saad, Iterative Methods for Sparse Linear Systems, Second Edition,
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! SIAM, 2003, Chapter 10.
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!
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! The local matrix to be factorized is stored into a and blck, as specified in
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! the description of the arguments below. The storage format for both the L and
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! U factors is CSR. The diagonal of the U factor is stored separately (actually,
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! the inverse of the diagonal entries is stored; this is then managed in the solve
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! stage associated to the ILU(k,t) factorization).
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!
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!
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! Arguments:
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! fill_in - integer, input.
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! The fill-in parameter k in ILU(k,t).
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! thres - integer, input.
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! The threshold t, i.e. the drop tolerance, in ILU(k,t).
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! a - type(psb_zspmat_type), input.
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! The sparse matrix structure containing the local matrix to be
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! factorized. Note that if the 'base' Additive Schwarz preconditioner
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! has overlap greater than 0 and the matrix has not been reordered
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! (see mld_bjac_bld), then a contains only the 'original' local part
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! of the matrix to be factorized, i.e. the rows of the matrix held
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! by the calling process according to the initial data distribution.
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! l - type(psb_zspmat_type), input/output.
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! The L factor in the incomplete factorization.
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! Note: its allocation is managed by the calling routine mld_ilu_bld,
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! hence it cannot be only intent(out).
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! u - type(psb_zspmat_type), input/output.
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! The U factor (except its diagonal) in the incomplete factorization.
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! Note: its allocation is managed by the calling routine mld_ilu_bld,
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! hence it cannot be only intent(out).
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! d - complex(kind(1.d0)), dimension(:), input/output.
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! The inverse of the diagonal entries of the U factor in the incomplete
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! factorization.
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! Note: its allocation is managed by the calling routine mld_ilu_bld,
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! hence it cannot be only intent(out).
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! info - integer, output.
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! Error code.
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! blck - type(psb_zspmat_type), input, optional, target.
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! The sparse matrix structure containing the remote rows of the
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! matrix to be factorized, that have been retrieved by mld_asmat_bld
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! to build an Additive Schwarz base preconditioner with overlap
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! greater than 0. If the overlap is 0 or the matrix has been reordered
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! (see mld_bjac_bld), then blck does not contain any row.
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!
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subroutine mld_zilut_fct(fill_in,thres,a,l,u,d,info,blck)
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use psb_base_mod
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use mld_prec_mod, mld_protect_name => mld_zilut_fct
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implicit none
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! Arguments
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integer, intent(in) :: fill_in
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real(kind(1.d0)), intent(in) :: thres
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integer, intent(out) :: info
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type(psb_zspmat_type),intent(in) :: a
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type(psb_zspmat_type),intent(inout) :: l,u
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complex(kind(1.d0)), intent(inout) :: d(:)
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type(psb_zspmat_type),intent(in), optional, target :: blck
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! Local Variables
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integer :: l1, l2, m, err_act
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type(psb_zspmat_type), pointer :: blck_
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character(len=20) :: name, ch_err
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name='mld_zilut_fct'
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info = 0
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call psb_erractionsave(err_act)
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if (fill_in < 0) then
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info=35
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call psb_errpush(info,name,i_err=(/1,fill_in,0,0,0/))
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goto 9999
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end if
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!
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! Point to / allocate memory for the incomplete factorization
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!
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if (present(blck)) then
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blck_ => blck
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else
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allocate(blck_,stat=info)
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if (info /= 0) then
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call psb_errpush(4010,name,a_err='Allocate')
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goto 9999
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end if
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call psb_sp_all(0,0,blck_,1,info)
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if (info /= 0) then
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info=4010
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ch_err='psb_sp_all'
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call psb_errpush(info,name,a_err=ch_err)
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goto 9999
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end if
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endif
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!
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! Compute the ILU(k,t) factorization
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!
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call mld_zilut_fctint(fill_in,thres,m,a,blck_,&
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& d,l%aspk,l%ia1,l%ia2,u%aspk,u%ia1,u%ia2,l1,l2,info)
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if (info /= 0) then
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info=4010
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ch_err='mld_zilut_fctint'
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call psb_errpush(info,name,a_err=ch_err)
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goto 9999
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end if
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!
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! Store information on the L and U sparse matrices
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!
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l%infoa(1) = l1
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l%fida = 'CSR'
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l%descra = 'TLU'
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u%infoa(1) = l2
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u%fida = 'CSR'
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u%descra = 'TUU'
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l%m = m
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l%k = m
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u%m = m
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u%k = m
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!
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! Nullify the pointer / deallocate the memory
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!
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if (present(blck)) then
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blck_ => null()
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else
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call psb_sp_free(blck_,info)
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if (info /= 0) then
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info=4010
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ch_err='psb_sp_free'
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call psb_errpush(info,name,a_err=ch_err)
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goto 9999
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end if
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deallocate(blck_)
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endif
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call psb_erractionrestore(err_act)
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return
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9999 continue
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call psb_erractionrestore(err_act)
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if (err_act.eq.psb_act_abort_) then
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call psb_error()
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return
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end if
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return
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contains
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!
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! Subroutine: mld_zilut_fctint
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! Version: real
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! Note: internal subroutine of mld_zilut_fct
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|
!
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|
! This routine computes the ILU(k,t) factorization of the local part of the
|
|
! matrix stored into a. These factorization is used to build the 'base
|
|
! preconditioner' (block-Jacobi preconditioner/solver, Additive Schwarz
|
|
! preconditioner) corresponding to a certain level of a multilevel preconditioner.
|
|
!
|
|
! The local matrix to be factorized is stored into a and b, as specified in the
|
|
! description of the arguments below. The storage format for both the L and U
|
|
! factors is CSR. The diagonal of the U factor is stored separately (actually,
|
|
! the inverse of the diagonal entries is stored; this is then managed in the
|
|
! solve stage associated to the ILU(k,t) factorization).
|
|
!
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|
!
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! Arguments:
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|
! fill_in - integer, input.
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|
! The fill-in parameter k in ILU(k,t).
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|
! thres - integer, input.
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|
! The threshold t, i.e. the drop tolerance, in ILU(k,t).
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|
! m - integer, output.
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! The total number of rows of the local matrix to be factorized,
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! i.e. ma+mb.
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! a - type(psb_zspmat_type), input.
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|
! The sparse matrix structure containing the local matrix to be
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|
! factorized. Note that, if the 'base' Additive Schwarz preconditioner
|
|
! has overlap greater than 0 and the matrix has not been reordered
|
|
! (see mld_bjac_bld), then a contains only the 'original' local part
|
|
! of the matrix to be factorized, i.e. the rows of the matrix held
|
|
! by the calling process according to the initial data distribution.
|
|
! b - type(psb_zspmat_type), input.
|
|
! The sparse matrix structure containing the remote rows of the
|
|
! matrix to be factorized, that have been retrieved by mld_asmat_bld
|
|
! to build an Additive Schwarz base preconditioner with overlap
|
|
! greater than 0. If the overlap is 0 or the matrix has been reordered
|
|
! (see mld_bjac_bld), then b does not contain any row.
|
|
! d - complex(kind(1.d0)), dimension(:), output.
|
|
! The inverse of the diagonal entries of the U factor in the incomplete
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|
! factorization.
|
|
! laspk - complex(kind(1.d0)), dimension(:), input/output.
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|
! The L factor in the incomplete factorization.
|
|
! lia1 - integer, dimension(:), input/output.
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|
! The column indices of the nonzero entries of the L factor,
|
|
! according to the CSR storage format.
|
|
! lia2 - integer, dimension(:), input/output.
|
|
! The indices identifying the first nonzero entry of each row
|
|
! of the L factor in laspk, according to the CSR storage format.
|
|
! uaspk - complex(kind(1.d0)), dimension(:), input/output.
|
|
! The U factor in the incomplete factorization.
|
|
! The entries of U are stored according to the CSR format.
|
|
! uia1 - integer, dimension(:), input/output.
|
|
! The column indices of the nonzero entries of the U factor,
|
|
! according to the CSR storage format.
|
|
! uia2 - integer, dimension(:), input/output.
|
|
! The indices identifying the first nonzero entry of each row
|
|
! of the U factor in uaspk, according to the CSR storage format.
|
|
! l1 - integer, output
|
|
! The number of nonzero entries in laspk.
|
|
! l2 - integer, output
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|
! The number of nonzero entries in uaspk.
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|
! info - integer, output.
|
|
! Error code.
|
|
!
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|
subroutine mld_zilut_fctint(fill_in,thres,m,a,b,&
|
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& d,laspk,lia1,lia2,uaspk,uia1,uia2,l1,l2,info)
|
|
|
|
use psb_base_mod
|
|
|
|
implicit none
|
|
|
|
! Arguments
|
|
integer, intent(in) :: fill_in
|
|
real(kind(1.d0)), intent(in) :: thres
|
|
type(psb_zspmat_type), intent(in) :: a,b
|
|
integer, intent(inout) :: m,l1,l2,info
|
|
integer, allocatable, intent(inout) :: lia1(:),lia2(:),uia1(:),uia2(:)
|
|
complex(kind(1.d0)), allocatable, intent(inout) :: laspk(:),uaspk(:)
|
|
complex(kind(1.d0)), intent(inout) :: d(:)
|
|
|
|
! Local Variables
|
|
integer :: i, ktrw,err_act,nidx,nlw,nup,jmaxup, ma, mb
|
|
real(kind(1.d0)) :: nrmi
|
|
integer, allocatable :: idxs(:)
|
|
complex(kind(1.d0)), allocatable :: row(:)
|
|
type(psb_int_heap) :: heap
|
|
type(psb_zspmat_type) :: trw
|
|
character(len=20), parameter :: name='mld_zilut_fctint'
|
|
|
|
if (psb_get_errstatus() /= 0) return
|
|
info = 0
|
|
call psb_erractionsave(err_act)
|
|
|
|
|
|
ma = a%m
|
|
mb = b%m
|
|
m = ma+mb
|
|
|
|
!
|
|
! Allocate a temporary buffer for the ilut_copyin function
|
|
!
|
|
call psb_sp_all(0,0,trw,1,info)
|
|
if (info==0) call psb_ensure_size(m+1,lia2,info)
|
|
if (info==0) call psb_ensure_size(m+1,uia2,info)
|
|
|
|
if (info /= 0) then
|
|
info=4010
|
|
call psb_errpush(info,name,a_err='psb_sp_all')
|
|
goto 9999
|
|
end if
|
|
|
|
l1=0
|
|
l2=0
|
|
lia2(1) = 1
|
|
uia2(1) = 1
|
|
|
|
!
|
|
! Allocate memory to hold the entries of a row
|
|
!
|
|
allocate(row(m),stat=info)
|
|
if (info /= 0) then
|
|
info=4010
|
|
call psb_errpush(info,name,a_err='Allocate')
|
|
goto 9999
|
|
end if
|
|
|
|
row(:) = zzero
|
|
|
|
!
|
|
! Cycle over the matrix rows
|
|
!
|
|
do i = 1, m
|
|
|
|
!
|
|
! At each iteration of the loop we keep in a heap the column indices
|
|
! affected by the factorization. The heap is initialized and filled
|
|
! in the ilut_copyin function, and updated during the elimination, in
|
|
! the ilut_fact routine. The heap is ideal because at each step we need
|
|
! the lowest index, but we also need to insert new items, and the heap
|
|
! allows to do both in log time.
|
|
!
|
|
d(i) = zzero
|
|
if (i<=ma) then
|
|
call ilut_copyin(i,ma,a,i,1,m,nlw,nup,jmaxup,nrmi,row,heap,ktrw,trw,info)
|
|
else
|
|
call ilut_copyin(i-ma,mb,b,i,1,m,nlw,nup,jmaxup,nrmi,row,heap,ktrw,trw,info)
|
|
endif
|
|
|
|
!
|
|
! Do an elimination step on current row
|
|
!
|
|
if (info == 0) call ilut_fact(thres,i,nrmi,row,heap,&
|
|
& d,uia1,uia2,uaspk,nidx,idxs,info)
|
|
!
|
|
! Copy the row into laspk/d(i)/uaspk
|
|
!
|
|
if (info == 0) call ilut_copyout(fill_in,thres,i,m,nlw,nup,jmaxup,nrmi,row,nidx,idxs,&
|
|
& l1,l2,lia1,lia2,laspk,d,uia1,uia2,uaspk,info)
|
|
|
|
if (info /= 0) then
|
|
info=4001
|
|
call psb_errpush(info,name,a_err='Copy/factor loop')
|
|
goto 9999
|
|
end if
|
|
|
|
end do
|
|
|
|
!
|
|
! And we're done, so deallocate the memory
|
|
!
|
|
deallocate(row,idxs,stat=info)
|
|
if (info /= 0) then
|
|
info=4010
|
|
call psb_errpush(info,name,a_err='Deallocate')
|
|
goto 9999
|
|
end if
|
|
if (info == 0) call psb_sp_free(trw,info)
|
|
if (info /= 0) then
|
|
info=4010
|
|
ch_err='psb_sp_free'
|
|
call psb_errpush(info,name,a_err=ch_err)
|
|
goto 9999
|
|
end if
|
|
|
|
call psb_erractionrestore(err_act)
|
|
return
|
|
|
|
9999 continue
|
|
call psb_erractionrestore(err_act)
|
|
if (err_act.eq.psb_act_abort_) then
|
|
call psb_error()
|
|
return
|
|
end if
|
|
return
|
|
end subroutine mld_zilut_fctint
|
|
|
|
!
|
|
! Subroutine: ilut_copyin
|
|
! Version: complex
|
|
! Note: internal subroutine of mld_zilut_fct
|
|
!
|
|
! This routine performs the following tasks:
|
|
! - copying a row of a sparse matrix A, stored in the sparse matrix structure a,
|
|
! into the array row;
|
|
! - storing into a heap the column indices of the nonzero entries of the copied
|
|
! row;
|
|
! - computing the column index of the first entry with maximum absolute value
|
|
! in the part of the row belonging to the upper triangle;
|
|
! - computing the 2-norm of the row.
|
|
! The output array row is such that it contains a full row of A, i.e. it contains
|
|
! also the zero entries of the row. This is useful for the elimination step
|
|
! performed by ilut_fact after the call to ilut_copyin (see mld_ilut_fctint).
|
|
!
|
|
! If the sparse matrix is in CSR format, a 'straight' copy is performed;
|
|
! otherwise psb_sp_getblk is used to extract a block of rows, which is then
|
|
! copied, row by row, into the array row, through successive calls to
|
|
! ilut_copyin.
|
|
!
|
|
! This routine is used by mld_zilut_fctint in the computation of the ILU(k,t)
|
|
! factorization of a local sparse matrix.
|
|
!
|
|
!
|
|
! Arguments:
|
|
! i - integer, input.
|
|
! The local index of the row to be extracted from the
|
|
! sparse matrix structure a.
|
|
! m - integer, input.
|
|
! The number of rows of the local matrix stored into a.
|
|
! a - type(psb_zspmat_type), input.
|
|
! The sparse matrix structure containing the row to be
|
|
! copied.
|
|
! jd - integer, input.
|
|
! The column index of the diagonal entry of the row to be
|
|
! copied.
|
|
! jmin - integer, input.
|
|
! The minimum valid column index.
|
|
! jmax - integer, input.
|
|
! The maximum valid column index.
|
|
! The output matrix will contain a clipped copy taken from
|
|
! a(1:m,jmin:jmax).
|
|
! nlw - integer, output.
|
|
! The number of nonzero entries in the part of the row
|
|
! belonging to the lower triangle of the matrix.
|
|
! nup - integer, output.
|
|
! The number of nonzero entries in the part of the row
|
|
! belonging to the upper triangle of the matrix.
|
|
! jmaxup - integer, output.
|
|
! The column index of the first entry with maximum absolute
|
|
! value in the part of the row belonging to the upper triangle
|
|
! nrmi - real(kind(1.d0)), output.
|
|
! The 2-norm of the current row.
|
|
! row - complex(kind(1.d0)), dimension(:), input/output.
|
|
! In input it is the null vector (see mld_ilut_fctint and
|
|
! ilut_copyout). In output it contains the row extracted
|
|
! from the matrix A. It actually contains a full row, i.e.
|
|
! it contains also the zero entries of the row.
|
|
! rowlevs - integer, dimension(:), input/output.
|
|
! In input rowlevs(k) = -(m+1) for k=1,...,m. In output
|
|
! rowlevs(k) = 0 for 1 <= k <= jmax and A(i,k) /=0, for
|
|
! future use in ilut_fact.
|
|
! heap - type(psb_int_heap), input/output.
|
|
! The heap containing the column indices of the nonzero
|
|
! entries in the array row.
|
|
! Note: this argument is intent(inout) and not only intent(out)
|
|
! to retain its allocation, done by psb_init_heap inside this
|
|
! routine.
|
|
! ktrw - integer, input/output.
|
|
! The index identifying the last entry taken from the
|
|
! staging buffer trw. See below.
|
|
! trw - type(psb_zspmat_type), input/output.
|
|
! A staging buffer. If the matrix A is not in CSR format, we use
|
|
! the psb_sp_getblk routine and store its output in trw; when we
|
|
! need to call psb_sp_getblk we do it for a block of rows, and then
|
|
! we consume them from trw in successive calls to this routine,
|
|
! until we empty the buffer. Thus we will make a call to psb_sp_getblk
|
|
! every nrb calls to copyin. If A is in CSR format it is unused.
|
|
!
|
|
subroutine ilut_copyin(i,m,a,jd,jmin,jmax,nlw,nup,jmaxup,nrmi,row,heap,ktrw,trw,info)
|
|
use psb_base_mod
|
|
implicit none
|
|
type(psb_zspmat_type), intent(in) :: a
|
|
type(psb_zspmat_type), intent(inout) :: trw
|
|
integer, intent(in) :: i, m,jmin,jmax,jd
|
|
integer, intent(inout) :: ktrw,nlw,nup,jmaxup,info
|
|
real(kind(1.d0)), intent(inout) :: nrmi
|
|
complex(kind(1.d0)), intent(inout) :: row(:)
|
|
type(psb_int_heap), intent(inout) :: heap
|
|
|
|
integer :: k,j,irb,kin,nz
|
|
integer, parameter :: nrb=16
|
|
real(kind(1.d0)) :: dmaxup
|
|
real(kind(1.d0)), external :: dznrm2
|
|
character(len=20), parameter :: name='mld_zilut_fctint'
|
|
|
|
if (psb_get_errstatus() /= 0) return
|
|
info = 0
|
|
call psb_erractionsave(err_act)
|
|
|
|
call psb_init_heap(heap,info)
|
|
if (info /= 0) then
|
|
info=4010
|
|
call psb_errpush(info,name,a_err='psb_init_heap')
|
|
goto 9999
|
|
end if
|
|
|
|
!
|
|
! nrmi is the norm of the current sparse row (for the time being,
|
|
! we use the 2-norm).
|
|
! NOTE: the 2-norm below includes also elements that are outside
|
|
! [jmin:jmax] strictly. Is this really important? TO BE CHECKED.
|
|
!
|
|
|
|
nlw = 0
|
|
nup = 0
|
|
jmaxup = 0
|
|
dmaxup = dzero
|
|
nrmi = dzero
|
|
|
|
if (toupper(a%fida)=='CSR') then
|
|
|
|
!
|
|
! Take a fast shortcut if the matrix is stored in CSR format
|
|
!
|
|
|
|
do j = a%ia2(i), a%ia2(i+1) - 1
|
|
k = a%ia1(j)
|
|
if ((jmin<=k).and.(k<=jmax)) then
|
|
row(k) = a%aspk(j)
|
|
call psb_insert_heap(k,heap,info)
|
|
if (info /= 0) then
|
|
info=4010
|
|
call psb_errpush(info,name,a_err='psb_insert_heap')
|
|
goto 9999
|
|
end if
|
|
end if
|
|
if (k<jd) nlw = nlw + 1
|
|
if (k>jd) then
|
|
nup = nup + 1
|
|
if (abs(row(k))>dmaxup) then
|
|
jmaxup = k
|
|
dmaxup = abs(row(k))
|
|
end if
|
|
end if
|
|
end do
|
|
nz = a%ia2(i+1) - a%ia2(i)
|
|
nrmi = dznrm2(nz,a%aspk(a%ia2(i)),ione)
|
|
else
|
|
|
|
!
|
|
! Otherwise use psb_sp_getblk, slower but able (in principle) of
|
|
! handling any format. In this case, a block of rows is extracted
|
|
! instead of a single row, for performance reasons, and these
|
|
! rows are copied one by one into the array row, through successive
|
|
! calls to ilut_copyin.
|
|
!
|
|
|
|
if ((mod(i,nrb) == 1).or.(nrb==1)) then
|
|
irb = min(m-i+1,nrb)
|
|
call psb_sp_getblk(i,a,trw,info,lrw=i+irb-1)
|
|
if (info /= 0) then
|
|
info=4010
|
|
call psb_errpush(info,name,a_err='psb_sp_getblk')
|
|
goto 9999
|
|
end if
|
|
ktrw=1
|
|
end if
|
|
|
|
kin = ktrw
|
|
do
|
|
if (ktrw > trw%infoa(psb_nnz_)) exit
|
|
if (trw%ia1(ktrw) > i) exit
|
|
k = trw%ia2(ktrw)
|
|
if ((jmin<=k).and.(k<=jmax)) then
|
|
row(k) = trw%aspk(ktrw)
|
|
call psb_insert_heap(k,heap,info)
|
|
if (info /= 0) then
|
|
info=4010
|
|
call psb_errpush(info,name,a_err='psb_insert_heap')
|
|
goto 9999
|
|
end if
|
|
end if
|
|
if (k<jd) nlw = nlw + 1
|
|
if (k>jd) then
|
|
nup = nup + 1
|
|
if (abs(row(k))>dmaxup) then
|
|
jmaxup = k
|
|
dmaxup = abs(row(k))
|
|
end if
|
|
end if
|
|
ktrw = ktrw + 1
|
|
enddo
|
|
nz = ktrw - kin
|
|
nrmi = dznrm2(nz,trw%aspk(kin),ione)
|
|
end if
|
|
call psb_erractionrestore(err_act)
|
|
return
|
|
|
|
9999 continue
|
|
call psb_erractionrestore(err_act)
|
|
if (err_act.eq.psb_act_abort_) then
|
|
call psb_error()
|
|
return
|
|
end if
|
|
return
|
|
|
|
end subroutine ilut_copyin
|
|
|
|
!
|
|
! Subroutine: ilut_fact
|
|
! Version: complex
|
|
! Note: internal subroutine of mld_zilut_fct
|
|
!
|
|
! This routine does an elimination step of the ILU(k,t) factorization on a single
|
|
! matrix row (see the calling routine mld_ilut_fctint). Actually, only the dropping
|
|
! rule based on the threshold is applied here. The dropping rule based on the
|
|
! fill-in is applied by ilut_copyout.
|
|
!
|
|
! The routine is used by mld_zilut_fctint in the computation of the ILU(k,t)
|
|
! factorization of a local sparse matrix.
|
|
!
|
|
!
|
|
! Arguments
|
|
! thres - integer, input.
|
|
! The threshold t, i.e. the drop tolerance, in ILU(k,t).
|
|
! i - integer, input.
|
|
! The local index of the row to which the factorization is applied.
|
|
! nrmi - real(kind(1.d0)), input.
|
|
! The 2-norm of the row to which the elimination step has to be
|
|
! applied.
|
|
! row - complex(kind(1.d0)), dimension(:), input/output.
|
|
! In input it contains the row to which the elimination step
|
|
! has to be applied. In output it contains the row after the
|
|
! elimination step. It actually contains a full row, i.e.
|
|
! it contains also the zero entries of the row.
|
|
! heap - type(psb_int_heap), input/output.
|
|
! The heap containing the column indices of the nonzero entries
|
|
! in the processed row. In input it contains the indices concerning
|
|
! the row before the elimination step, while in output it contains
|
|
! the previous indices plus the ones corresponding to transformed
|
|
! entries in the 'upper part' that have not been dropped.
|
|
! d - complex(kind(1.d0)), input.
|
|
! The inverse of the diagonal entries of the part of the U factor
|
|
! above the current row (see ilut_copyout).
|
|
! uia1 - integer, dimension(:), input.
|
|
! The column indices of the nonzero entries of the part of the U
|
|
! factor above the current row, stored in uaspk row by row (see
|
|
! ilut_copyout, called by mld_zilut_fctint), according to the CSR
|
|
! storage format.
|
|
! uia2 - integer, dimension(:), input.
|
|
! The indices identifying the first nonzero entry of each row of
|
|
! the U factor above the current row, stored in uaspk row by row
|
|
! (see ilut_copyout, called by mld_zilut_fctint), according to
|
|
! the CSR storage format.
|
|
! uaspk - complex(kind(1.d0)), dimension(:), input.
|
|
! The entries of the U factor above the current row (except the
|
|
! diagonal ones), stored according to the CSR format.
|
|
! nidx - integer, output.
|
|
! The number of entries of the array row that have been
|
|
! examined during the elimination step. This will be used
|
|
! by the routine ilut_copyout.
|
|
! idxs - integer, dimension(:), allocatable, input/output.
|
|
! The indices of the entries of the array row that have been
|
|
! examined during the elimination step.This will be used by
|
|
! by the routine ilut_copyout.
|
|
! Note: this argument is intent(inout) and not only intent(out)
|
|
! to retain its allocation, done by this routine.
|
|
!
|
|
subroutine ilut_fact(thres,i,nrmi,row,heap,d,uia1,uia2,uaspk,nidx,idxs,info)
|
|
|
|
use psb_base_mod
|
|
|
|
implicit none
|
|
|
|
! Arguments
|
|
type(psb_int_heap), intent(inout) :: heap
|
|
integer, intent(in) :: i
|
|
integer, intent(inout) :: nidx,info
|
|
real(kind(1.d0)), intent(in) :: thres,nrmi
|
|
integer, allocatable, intent(inout) :: idxs(:)
|
|
integer, intent(inout) :: uia1(:),uia2(:)
|
|
complex(kind(1.d0)), intent(inout) :: row(:), uaspk(:),d(:)
|
|
|
|
! Local Variables
|
|
integer :: k,j,jj,lastk, iret
|
|
complex(kind(1.d0)) :: rwk
|
|
|
|
info = 0
|
|
call psb_ensure_size(200,idxs,info)
|
|
if (info /= 0) return
|
|
nidx = 0
|
|
lastk = -1
|
|
!
|
|
! Do while there are indices to be processed
|
|
!
|
|
do
|
|
|
|
call psb_heap_get_first(k,heap,iret)
|
|
if (iret < 0) exit
|
|
|
|
!
|
|
! An index may have been put on the heap more than once.
|
|
!
|
|
if (k == lastk) cycle
|
|
|
|
lastk = k
|
|
lowert: if (k<i) then
|
|
|
|
!
|
|
! Dropping rule based on the threshold: compare the absolute
|
|
! value of each updated entry of row with thres * 2-norm of row.
|
|
!
|
|
rwk = row(k)
|
|
row(k) = row(k) * d(k)
|
|
if (abs(row(k)) < thres*nrmi) then
|
|
!
|
|
! Drop the entry.
|
|
!
|
|
row(k) = zzero
|
|
cycle
|
|
else
|
|
!
|
|
! Note: since U is scaled while copying it out (see ilut_copyout),
|
|
! we can use rwk in the update below.
|
|
!
|
|
do jj=uia2(k),uia2(k+1)-1
|
|
j = uia1(jj)
|
|
if (j<=k) then
|
|
info = -i
|
|
return
|
|
endif
|
|
!
|
|
! Update row(j) and, if it is not to be discarded, insert
|
|
! its index into the heap for further processing.
|
|
!
|
|
row(j) = row(j) - rwk * uaspk(jj)
|
|
if (abs(row(j)) < thres*nrmi) then
|
|
!
|
|
! Drop the entry.
|
|
!
|
|
row(j) = zzero
|
|
else
|
|
!
|
|
! Do the insertion.
|
|
!
|
|
call psb_insert_heap(j,heap,info)
|
|
if (info /= 0) return
|
|
endif
|
|
end do
|
|
end if
|
|
end if lowert
|
|
|
|
!
|
|
! If we get here it is an index we need to keep on copyout.
|
|
!
|
|
nidx = nidx + 1
|
|
call psb_ensure_size(nidx,idxs,info,addsz=psb_heap_resize)
|
|
if (info /= 0) return
|
|
idxs(nidx) = k
|
|
|
|
end do
|
|
|
|
end subroutine ilut_fact
|
|
|
|
!
|
|
! Subroutine: ilut_copyout
|
|
! Version: complex
|
|
! Note: internal subroutine of mld_zilut_fct
|
|
!
|
|
! This routine copies a matrix row, computed by ilut_fact by applying an
|
|
! elimination step of the ILU(k,t) factorization, into the arrays laspk,
|
|
! uaspk, d, corresponding to the L factor, the U factor and the diagonal
|
|
! of U, respectively.
|
|
!
|
|
! Note that
|
|
! - the dropping rule based on the fill-in is applied here and not in ilut_fact;
|
|
! it consists in keeping the nlw+k entries with largest absolute value in
|
|
! the 'lower part' of the row, and the nup+k ones in the 'upper part';
|
|
! - the entry in the upper part of the row which has maximum absolute value
|
|
! in the original matrix is included in the above nup+k entries anyway;
|
|
! - the part of the row stored into uaspk is scaled by the corresponding
|
|
! diagonal entry, according to the LDU form of the incomplete factorization;
|
|
! - the inverse of the diagonal entries of U is actually stored into d; this
|
|
! is then managed in the solve stage associated to the ILU(k,t) factorization;
|
|
! - the row entries are stored in laspk and uaspk according to the CSR format;
|
|
! - the array row is re-initialized for future use in mld_ilut_fct(see also
|
|
! ilut_copyin and ilut_fact).
|
|
!
|
|
! This routine is used by mld_zilut_fctint in the computation of the ILU(k,t)
|
|
! factorization of a local sparse matrix.
|
|
!
|
|
!
|
|
! Arguments:
|
|
! fill_in - integer, input.
|
|
! The fill-in parameter k in ILU(k,t).
|
|
! thres - integer, input.
|
|
! The threshold t, i.e. the drop tolerance, in ILU(k,t).
|
|
! i - integer, input.
|
|
! The local index of the row to be copied.
|
|
! m - integer, input.
|
|
! The number of rows of the local matrix under factorization.
|
|
! nlw - integer, input.
|
|
! The number of nonzero entries of the 'lower part' of the row
|
|
! in the initial matrix (i.e. the matrix before the factorization).
|
|
! nup - integer, input.
|
|
! The number of nonzero entries in the 'upper part' of the row
|
|
! in the initial matrix.
|
|
! jmaxup - integer, input.
|
|
! The column index of the first entry with maximum absolute
|
|
! value in the 'upper part' of the row in the initial matrix.
|
|
! nrmi - real(kind(1.d0)), input.
|
|
! The 2-norm of the current row in the initial matrix.
|
|
! row - complex(kind(1.d0)), dimension(:), input/output.
|
|
! It contains, input, the row to be copied, and, in output,
|
|
! the null vector (the latter is used in the next call to
|
|
! ilut_copyin in mld_ilut_fact).
|
|
! nidx - integer, input.
|
|
! The number of entries of the array row that have been examined
|
|
! during the elimination step carried out by the routine ilut_fact.
|
|
! idxs - integer, dimension(:), allocatable, input.
|
|
! The indices of the entries of the array row that have been
|
|
! examined during the elimination step carried out by the routine
|
|
! ilut_fact.
|
|
! l1 - integer, input/output.
|
|
! Pointer to the last occupied entry of laspk.
|
|
! l2 - integer, input/output.
|
|
! Pointer to the last occupied entry of uaspk.
|
|
! lia1 - integer, dimension(:), input/output.
|
|
! The column indices of the nonzero entries of the L factor,
|
|
! copied in laspk row by row (see mld_zilut_fctint), according
|
|
! to the CSR storage format.
|
|
! lia2 - integer, dimension(:), input/output.
|
|
! The indices identifying the first nonzero entry of each row
|
|
! of the L factor, copied in laspk row by row (see
|
|
! mld_zilut_fctint), according to the CSR storage format.
|
|
! laspk - complex(kind(1.d0)), dimension(:), input/output.
|
|
! The array where the entries of the row corresponding to the
|
|
! L factor are copied.
|
|
! d - complex(kind(1.d0)), dimension(:), input/output.
|
|
! The array where the inverse of the diagonal entry of the
|
|
! row is copied (only d(i) is used by the routine).
|
|
! uia1 - integer, dimension(:), input/output.
|
|
! The column indices of the nonzero entries of the U factor
|
|
! copied in uaspk row by row (see mld_zilut_fctint), according
|
|
! to the CSR storage format.
|
|
! uia2 - integer, dimension(:), input/output.
|
|
! The indices identifying the first nonzero entry of each row
|
|
! of the U factor copied in uaspk row by row (see
|
|
! mld_zilu_fctint), according to the CSR storage format.
|
|
! uaspk - complex(kind(1.d0)), dimension(:), input/output.
|
|
! The array where the entries of the row corresponding to the
|
|
! U factor are copied.
|
|
!
|
|
subroutine ilut_copyout(fill_in,thres,i,m,nlw,nup,jmaxup,nrmi,row, &
|
|
& nidx,idxs,l1,l2,lia1,lia2,laspk,d,uia1,uia2,uaspk,info)
|
|
|
|
use psb_base_mod
|
|
|
|
implicit none
|
|
|
|
! Arguments
|
|
integer, intent(in) :: fill_in,i,m,nidx,nlw,nup,jmaxup
|
|
integer, intent(in) :: idxs(:)
|
|
integer, intent(inout) :: l1,l2, info
|
|
integer, allocatable, intent(inout) :: uia1(:),uia2(:), lia1(:),lia2(:)
|
|
real(kind(1.d0)), intent(in) :: thres,nrmi
|
|
complex(kind(1.d0)),allocatable, intent(inout) :: uaspk(:), laspk(:)
|
|
complex(kind(1.d0)), intent(inout) :: row(:), d(:)
|
|
|
|
! Local variables
|
|
complex(kind(1.d0)),allocatable :: xw(:)
|
|
integer, allocatable :: xwid(:), indx(:)
|
|
complex(kind(1.d0)) :: witem
|
|
integer :: widx
|
|
integer :: k,isz,err_act,int_err(5),idxp, nz
|
|
type(psb_dcomplex_idx_heap) :: heap
|
|
character(len=20), parameter :: name='ilut_copyout'
|
|
character(len=20) :: ch_err
|
|
logical :: fndmaxup
|
|
|
|
if (psb_get_errstatus() /= 0) return
|
|
info=0
|
|
call psb_erractionsave(err_act)
|
|
|
|
!
|
|
! Here we need to apply also the dropping rule base on the fill-in.
|
|
! We do it by putting into a heap the elements that are not dropped
|
|
! by using the 2-norm rule, and then copying them out.
|
|
!
|
|
! The heap goes down on the entry absolute value, so the first item
|
|
! is the largest absolute value.
|
|
!
|
|
|
|
call psb_init_heap(heap,info,dir=psb_asort_down_)
|
|
|
|
if (info == 0) allocate(xwid(nidx),xw(nidx),indx(nidx),stat=info)
|
|
if (info /= 0) then
|
|
info=4025
|
|
call psb_errpush(info,name,i_err=(/3*nidx,0,0,0,0/),&
|
|
& a_err='complex(kind(1.d0))')
|
|
goto 9999
|
|
end if
|
|
|
|
!
|
|
! First the lower part
|
|
!
|
|
|
|
nz = 0
|
|
idxp = 0
|
|
|
|
do
|
|
|
|
idxp = idxp + 1
|
|
if (idxp > nidx) exit
|
|
if (idxs(idxp) >= i) exit
|
|
widx = idxs(idxp)
|
|
witem = row(widx)
|
|
!
|
|
! Dropping rule based on the 2-norm
|
|
!
|
|
if (abs(witem) < thres*nrmi) cycle
|
|
|
|
nz = nz + 1
|
|
xw(nz) = witem
|
|
xwid(nz) = widx
|
|
call psb_insert_heap(witem,widx,heap,info)
|
|
if (info /= 0) then
|
|
info=4010
|
|
call psb_errpush(info,name,a_err='psb_insert_heap')
|
|
goto 9999
|
|
end if
|
|
end do
|
|
|
|
!
|
|
! Now we have to take out the first nlw+fill_in entries
|
|
!
|
|
if (nz <= nlw+fill_in) then
|
|
!
|
|
! Just copy everything from xw, and it is already ordered
|
|
!
|
|
else
|
|
nz = nlw+fill_in
|
|
do k=1,nz
|
|
call psb_heap_get_first(witem,widx,heap,info)
|
|
if (info /= 0) then
|
|
info=4010
|
|
call psb_errpush(info,name,a_err='psb_heap_get_first')
|
|
goto 9999
|
|
end if
|
|
|
|
xw(k) = witem
|
|
xwid(k) = widx
|
|
end do
|
|
end if
|
|
|
|
!
|
|
! Now put things back into ascending column order
|
|
!
|
|
call psb_msort(xwid(1:nz),indx(1:nz),dir=psb_sort_up_)
|
|
|
|
!
|
|
! Copy out the lower part of the row
|
|
!
|
|
do k=1,nz
|
|
l1 = l1 + 1
|
|
if (size(laspk) < l1) then
|
|
!
|
|
! Figure out a good reallocation size!
|
|
!
|
|
isz = (max((l1/i)*m,int(1.2*l1),l1+100))
|
|
call psb_realloc(isz,laspk,info)
|
|
if (info == 0) call psb_realloc(isz,lia1,info)
|
|
if (info /= 0) then
|
|
info=4010
|
|
call psb_errpush(info,name,a_err='Allocate')
|
|
goto 9999
|
|
end if
|
|
end if
|
|
lia1(l1) = xwid(k)
|
|
laspk(l1) = xw(indx(k))
|
|
end do
|
|
|
|
!
|
|
! Make sure idxp points to the diagonal entry
|
|
!
|
|
if (idxp <= size(idxs)) then
|
|
if (idxs(idxp) < i) then
|
|
do
|
|
idxp = idxp + 1
|
|
if (idxp > nidx) exit
|
|
if (idxs(idxp) >= i) exit
|
|
end do
|
|
end if
|
|
end if
|
|
if (idxp > size(idxs)) then
|
|
!!$ write(0,*) 'Warning: missing diagonal element in the row '
|
|
else
|
|
if (idxs(idxp) > i) then
|
|
!!$ write(0,*) 'Warning: missing diagonal element in the row '
|
|
else if (idxs(idxp) /= i) then
|
|
!!$ write(0,*) 'Warning: impossible error: diagonal has vanished'
|
|
else
|
|
!
|
|
! Copy the diagonal entry
|
|
!
|
|
widx = idxs(idxp)
|
|
witem = row(widx)
|
|
d(i) = witem
|
|
if (abs(d(i)) < epstol) then
|
|
!
|
|
! Too small pivot: unstable factorization
|
|
!
|
|
info = 2
|
|
int_err(1) = i
|
|
write(ch_err,'(g20.10)') d(i)
|
|
call psb_errpush(info,name,i_err=int_err,a_err=ch_err)
|
|
goto 9999
|
|
else
|
|
!
|
|
! Compute 1/pivot
|
|
!
|
|
d(i) = done/d(i)
|
|
end if
|
|
end if
|
|
end if
|
|
|
|
!
|
|
! Now the upper part
|
|
!
|
|
|
|
call psb_init_heap(heap,info,dir=psb_asort_down_)
|
|
if (info /= 0) then
|
|
info=4010
|
|
call psb_errpush(info,name,a_err='psb_init_heap')
|
|
goto 9999
|
|
end if
|
|
|
|
nz = 0
|
|
do
|
|
|
|
idxp = idxp + 1
|
|
if (idxp > nidx) exit
|
|
widx = idxs(idxp)
|
|
if (widx <= i) then
|
|
!!$ write(0,*) 'Warning: lower triangle in upper copy',widx,i,idxp,idxs(idxp)
|
|
cycle
|
|
end if
|
|
if (widx > m) then
|
|
!!$ write(0,*) 'Warning: impossible value',widx,i,idxp,idxs(idxp)
|
|
cycle
|
|
end if
|
|
witem = row(widx)
|
|
!
|
|
! Dropping rule based on the 2-norm. But keep the jmaxup-th entry anyway.
|
|
!
|
|
if ((widx /= jmaxup) .and. (abs(witem) < thres*nrmi)) then
|
|
cycle
|
|
end if
|
|
|
|
nz = nz + 1
|
|
xw(nz) = witem
|
|
xwid(nz) = widx
|
|
call psb_insert_heap(witem,widx,heap,info)
|
|
if (info /= 0) then
|
|
info=4010
|
|
call psb_errpush(info,name,a_err='psb_insert_heap')
|
|
goto 9999
|
|
end if
|
|
|
|
end do
|
|
|
|
!
|
|
! Now we have to take out the first nup-fill_in entries. But make sure
|
|
! we include entry jmaxup.
|
|
!
|
|
if (nz <= nup+fill_in) then
|
|
!
|
|
! Just copy everything from xw
|
|
!
|
|
fndmaxup=.true.
|
|
else
|
|
fndmaxup = .false.
|
|
nz = nup+fill_in
|
|
do k=1,nz
|
|
call psb_heap_get_first(witem,widx,heap,info)
|
|
xw(k) = witem
|
|
xwid(k) = widx
|
|
if (widx == jmaxup) fndmaxup=.true.
|
|
end do
|
|
end if
|
|
if ((i<jmaxup).and.(jmaxup<=m)) then
|
|
if (.not.fndmaxup) then
|
|
!
|
|
! Include entry jmaxup, if it is not already there.
|
|
! Put it in the place of the smallest coefficient.
|
|
!
|
|
xw(nz) = row(jmaxup)
|
|
xwid(nz) = jmaxup
|
|
endif
|
|
end if
|
|
|
|
!
|
|
! Now we put things back into ascending column order
|
|
!
|
|
call psb_msort(xwid(1:nz),indx(1:nz),dir=psb_sort_up_)
|
|
|
|
!
|
|
! Copy out the upper part of the row
|
|
!
|
|
do k=1,nz
|
|
l2 = l2 + 1
|
|
if (size(uaspk) < l2) then
|
|
!
|
|
! Figure out a good reallocation size!
|
|
!
|
|
isz = max((l2/i)*m,int(1.2*l2),l2+100)
|
|
call psb_realloc(isz,uaspk,info)
|
|
if (info == 0) call psb_realloc(isz,uia1,info)
|
|
if (info /= 0) then
|
|
info=4010
|
|
call psb_errpush(info,name,a_err='Allocate')
|
|
goto 9999
|
|
end if
|
|
end if
|
|
uia1(l2) = xwid(k)
|
|
uaspk(l2) = d(i)*xw(indx(k))
|
|
end do
|
|
|
|
!
|
|
! Set row to zero
|
|
!
|
|
do idxp=1,nidx
|
|
row(idxs(idxp)) = zzero
|
|
end do
|
|
|
|
!
|
|
! Store the pointers to the first non occupied entry of in
|
|
! laspk and uaspk
|
|
!
|
|
lia2(i+1) = l1 + 1
|
|
uia2(i+1) = l2 + 1
|
|
|
|
call psb_erractionrestore(err_act)
|
|
return
|
|
|
|
9999 continue
|
|
call psb_erractionrestore(err_act)
|
|
if (err_act.eq.psb_act_abort_) then
|
|
call psb_error()
|
|
return
|
|
end if
|
|
|
|
end subroutine ilut_copyout
|
|
|
|
|
|
end subroutine mld_zilut_fct
|