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psblas3/prec/impl/psb_d_sparsify.f90

261 lines
8.5 KiB
Fortran

!
! Parallel Sparse BLAS version 3.5
! (C) Copyright 2006-2018
! Salvatore Filippone
! Alfredo Buttari
!
! 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 PSBLAS 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 PSBLAS 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.
!
! Moved here from AMG-AINV, original copyright below.
!
!
! AMG-AINV: Approximate Inverse plugin for
! AMG4PSBLAS version 1.0
!
! (C) Copyright 2020
!
! Salvatore Filippone University of Rome Tor Vergata
!
! 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.
!
!
subroutine psb_d_sparsify(idiag,nzrmax,sp_thresh,n,zw,nz,iz,valz,info,istart,iheap,ikr)
use psb_base_mod
implicit none
real(psb_dpk_), intent(in) :: sp_thresh
integer(psb_ipk_), intent(in) :: idiag, n, nzrmax
real(psb_dpk_), intent(inout) :: zw(:)
integer(psb_ipk_), intent(out) :: nz
integer(psb_ipk_), intent(out) :: iz(:)
real(psb_dpk_), intent(out) :: valz(:)
integer(psb_ipk_), intent(out) :: info
integer(psb_ipk_), intent(in), optional :: istart
type(psb_i_heap), optional :: iheap
integer(psb_ipk_), optional :: ikr(:)
!
integer(psb_ipk_) :: i, istart_, last_i, iret,k
real(psb_dpk_) :: witem
integer(psb_ipk_) :: widx
real(psb_dpk_), allocatable :: xw(:)
integer(psb_ipk_), allocatable :: xwid(:), indx(:)
type(psb_d_idx_heap) :: heap
info = psb_success_
istart_ = 1
if (present(istart)) istart_ = max(1,istart)
if (.false.) then
nz = 0
do i=istart_, n
if ((i == idiag).or.(abs(zw(i)) >= sp_thresh)) then
nz = nz + 1
iz(nz) = i
valz(nz) = zw(i)
end if
end do
else
allocate(xw(nzrmax),xwid(nzrmax),indx(nzrmax),stat=info)
if (info /= psb_success_) then
return
end if
call heap%init(info,dir=psb_asort_down_)
! Keep at least the diagonal
nz = 0
if (present(iheap)) then
if (.not.(present(ikr))) then
write(psb_err_unit,*) 'Error: if IHEAP then also IKR'
info = -1
return
end if
last_i = -1
do
call iheap%get_first(i,iret)
if (iret < 0) exit
! An index may have been put on the heap more than once.
if (i == last_i) cycle
last_i = i
if (i == idiag) then
xw(1) = zw(i)
xwid(1) = i
else if (abs(zw(i)) >= sp_thresh) then
call heap%insert(zw(i),i,info)
end if
zw(i) = dzero
ikr(i) = 0
end do
else
do i=istart_, n
if (i == idiag) then
xw(1) = zw(i)
xwid(1) = i
else if (abs(zw(i)) >= sp_thresh) then
call heap%insert(zw(i),i,info)
end if
zw(i) = dzero
end do
end if
k = 1
do
if (k == nzrmax) exit
call heap%get_first(witem,widx,info)
if (info == -1) then
info = psb_success_
exit
endif
if (info /= psb_success_) then
info=psb_err_from_subroutine_
return
end if
k = k + 1
xw(k) = witem
xwid(k) = widx
end do
call heap%free(info)
nz = k
call psb_msort(xwid(1:nz),indx(1:nz),dir=psb_sort_up_)
!!$ write(0,*) 'sparsify output for idiag ',idiag,' :',nz,sp_thresh
do i=1, nz
valz(i) = xw(indx(i))
iz(i) = xwid(i)
!!$ write(0,*) ' ',iz(i),valz(i)
end do
end if
return
end subroutine psb_d_sparsify
subroutine psb_d_sparsify_list(idiag,nzrmax,sp_thresh,n,zw,nz,iz,valz,lhead,listv,ikr,info)
use psb_base_mod
implicit none
real(psb_dpk_), intent(in) :: sp_thresh
integer(psb_ipk_), intent(in) :: idiag, n, nzrmax
real(psb_dpk_), intent(inout) :: zw(:)
integer(psb_ipk_), intent(out) :: nz
integer(psb_ipk_), intent(out) :: iz(:)
real(psb_dpk_), intent(out) :: valz(:)
integer(psb_ipk_), intent(out) :: info
integer(psb_ipk_), intent(inout) :: lhead, listv(:)
integer(psb_ipk_) :: ikr(:)
!
integer(psb_ipk_) :: i, istart_, last_i, iret,k,current, next
real(psb_dpk_) :: witem
integer(psb_ipk_) :: widx
real(psb_dpk_), allocatable :: xw(:)
integer(psb_ipk_), allocatable :: xwid(:), indx(:)
info = psb_success_
istart_ = 1
allocate(xw(n),xwid(n),indx(n),stat=info)
current = lhead
lhead = -1
i = 0
do while (current >0)
i = i + 1
xw(i) = zw(current)
xwid(i) = current
if (current == idiag) then
! Bring the diagona into first position
witem = xw(1)
widx = xwid(1)
xw(1) = xw(i)
xwid(1) = xwid(i)
xw(i) = witem
xwid(i) = widx
end if
zw(current) = dzero
ikr(current) = 0
next = listv(current)
listv(current) = -1
current = next
end do
nz = i
if (nz > 2) call psb_hsort(xw(2:nz),ix=xwid(2:nz),&
& dir=psb_asort_down_,flag=psb_sort_keep_idx_)
!!$ write(0,*) 'Done first msort '
!!$ write(0,*) ' after first msort for idiag ',idiag,' :',nz,sp_thresh
!!$ do i=1, nz
!!$ write(0,*) ' ',xwid(i),xw(i)
!!$ end do
i = 2
do while (i<=nz)
if (abs(xw(i)) < sp_thresh) exit
i = i + 1
end do
!!$ write(0,*) 'NZ ',nz, i, nzrmax
nz = max(1,min(i-1,nzrmax))
call psb_msort(xwid(1:nz),ix=indx(1:nz),dir=psb_sort_up_)
!!$ write(0,*) 'Done second msort '
!!$ write(0,*) 'sparsify output for idiag ',idiag,' :',nz,i,sp_thresh
do i=1, nz
valz(i) = xw(indx(i))
iz(i) = xwid(i)
!!$ write(0,*) ' ',iz(i),valz(i)
end do
return
end subroutine psb_d_sparsify_list