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Implementation of preconditioned MINRES

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minres
Fabio Durastante 2 days ago
parent 4a5acb014c
commit 3aceaa31eb
14 changed files with 2100 additions and 9 deletions
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4
linsolve/impl/CMakeLists.txt
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@ -42,6 +42,10 @@ set(PSB_krylov_source_files
psb_z_krylov_conv_mod.f90
psb_zkrylov.f90
psb_zrgmres.f90
psb_dminres.f90
psb_sminres.f90
psb_cminres.f90
psb_zminres.f90
)
foreach(file IN LISTS PSB_krylov_source_files)
list(APPEND krylov_source_files ${CMAKE_CURRENT_LIST_DIR}/${file})

3
linsolve/impl/Makefile
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@ -13,7 +13,8 @@ OBJS=psb_dkrylov.o psb_skrylov.o psb_ckrylov.o psb_zkrylov.o \
psb_ccgstab.o psb_ccg.o psb_cfcg.o psb_cgcr.o psb_ccgs.o \
psb_cbicg.o psb_ccgstabl.o psb_crgmres.o\
psb_zcgstab.o psb_zcg.o psb_zfcg.o psb_zgcr.o psb_zcgs.o \
psb_zbicg.o psb_zcgstabl.o psb_zrgmres.o
psb_zbicg.o psb_zcgstabl.o psb_zrgmres.o \
psb_dminres.o psb_sminres.o psb_cminres.o psb_zminres.o
LIBNAME=$(METHDLIBNAME)
COBJS=

5
linsolve/impl/psb_ckrylov.f90
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@ -150,7 +150,7 @@ Subroutine psb_ckrylov_vect(method,a,prec,b,x,eps,desc_a,info,&
procedure(psb_ckryl_vect) :: psb_cbicg_vect, psb_ccgstab_vect,&
& psb_ccgs_vect
procedure(psb_ckryl_rest_vect) :: psb_crgmres_vect, psb_ccgstabl_vect, psb_cgcr_vect
procedure(psb_ckryl_cond_vect) :: psb_ccg_vect, psb_cfcg_vect
procedure(psb_ckryl_cond_vect) :: psb_ccg_vect, psb_cfcg_vect, psb_cminres_vect
logical :: do_alloc_wrk
type(psb_ctxt_type) :: ctxt
@ -199,6 +199,9 @@ Subroutine psb_ckrylov_vect(method,a,prec,b,x,eps,desc_a,info,&
case('RGMRES','GMRES')
call psb_crgmres_vect(a,prec,b,x,eps,desc_a,info,&
&itmax,iter,err,itrace=itrace_,irst=irst,istop=istop)
case('MINRES','PMINRES')
call psb_cminres_vect(a,prec,b,x,eps,desc_a,info,&
&itmax,iter,err,itrace=itrace_,istop=istop)
case('BICGSTABL')
call psb_ccgstabl_vect(a,prec,b,x,eps,desc_a,info,&
&itmax,iter,err,itrace=itrace_,irst=irst,istop=istop)

511
linsolve/impl/psb_cminres.f90
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@ -0,0 +1,511 @@
!
! 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 prior 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.
!
!
! File: psb_cminres.f90
! CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
! C C
! C References: C
! C [1] Duff, I., Marrone, M., Radicati, G., and Vittoli, C. C
! C Level 3 basic linear algebra subprograms for sparse C
! C matrices: a user level interface C
! C ACM Trans. Math. Softw., 23(3), 379-401, 1997. C
! C C
! C C
! C [2] S. Filippone, M. Colajanni C
! C PSBLAS: A library for parallel linear algebra C
! C computation on sparse matrices C
! C ACM Trans. on Math. Softw., 26(4), 527-550, Dec. 2000. C
! C C
! C [3] M. Arioli, I. Duff, M. Ruiz C
! C Stopping criteria for iterative solvers C
! C SIAM J. Matrix Anal. Appl., Vol. 13, pp. 138-144, 1992 C
! C C
! C C
! C [4] R. Barrett et al C
! C Templates for the solution of linear systems C
! C SIAM, 1993
! C C
! C C
! CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
! File: psb_cminres.f90
!
! Subroutine: psb_cminres
! This subroutine implements the MINRES method.
!
!
! Arguments:
!
! a - type(psb_cspmat_type) Input: sparse matrix containing A.
! prec - class(psb_cprec_type) Input: preconditioner
! b(:) - complex Input: vector containing the
! right hand side B
! x(:) - complex Input/Output: vector containing the
! initial guess and final solution X.
! eps - real Input: Stopping tolerance; the iteration is
! stopped when the error estimate |err| <= eps
! desc_a - type(psb_desc_type). Input: The communication descriptor.
! info - integer. Output: Return code
!
! itmax - integer(optional) Input: maximum number of iterations to be
! performed.
! iter - integer(optional) Output: how many iterations have been
! performed.
! performed.
! err - real (optional) Output: error estimate on exit. If the
! denominator of the estimate is exactly
! 0, it is changed into 1.
! itrace - integer(optional) Input: print an informational message
! with the error estimate every itrace
! iterations
! istop - integer(optional) Input: stopping criterion, or how
! to estimate the error.
! 1: err = |r|/(|a||x|+|b|); here the iteration is
! stopped when |r| <= eps * (|a||x|+|b|)
! 2: err = |r|/|b|; here the iteration is
! stopped when |r| <= eps * |b|
! where r is the (preconditioned, recursive
! estimate of) residual.
!
!
subroutine psb_cminres_vect(a,prec,b,x,eps,desc_a,info,&
& itmax,iter,err,itrace,istop,cond)
use psb_base_mod
use psb_prec_mod
use psb_c_linsolve_conv_mod
use psb_linsolve_mod
implicit none
type(psb_cspmat_type), intent(in) :: a
Type(psb_desc_type), Intent(in) :: desc_a
class(psb_cprec_type), intent(inout) :: prec
type(psb_c_vect_type), Intent(inout) :: b
type(psb_c_vect_type), Intent(inout) :: x
Real(psb_spk_), Intent(in) :: eps
integer(psb_ipk_), intent(out) :: info
integer(psb_ipk_), Optional, Intent(in) :: itmax, itrace, istop
integer(psb_ipk_), Optional, Intent(out) :: iter
Real(psb_spk_), Optional, Intent(out) :: err, cond
! = Local data
complex(psb_spk_), allocatable, target :: aux(:)
type(psb_c_vect_type), allocatable, target :: wwrk(:)
type(psb_c_vect_type), pointer :: y, r1, r2, v, w, w1, w2, wtmp, res
complex(psb_spk_) :: alfa, beta, beta1, dbar, delta, denom
complex(psb_spk_) :: epsln, gamma, gbar, oldb, oldeps, phi, phibar
complex(psb_spk_) :: rhs1, rhs2, s, zeta, betatmp
complex(psb_spk_) :: rotx(1), roty(1)
real(psb_spk_) :: cs
complex(psb_spk_) :: sn
integer(psb_ipk_) :: itmax_, istop_, naux, itx, itrace_, n_col, n_row, err_act
integer(psb_lpk_) :: mglob
integer(psb_ipk_) :: debug_level, debug_unit
type(psb_ctxt_type) :: ctxt
integer(psb_ipk_) :: np, me
real(psb_dpk_) :: derr, errnum, errden, deps
logical :: do_cond
logical :: converged
real(psb_spk_) :: epsmach
real(psb_spk_) :: gmax, gmin, tnorm2, ynorm2
real(psb_spk_) :: rni, xni, bni, ani, bn2, r0n2
character(len=20) :: name
character(len=*), parameter :: methdname='MINRES'
info = psb_success_
name = 'psb_cminres'
call psb_erractionsave(err_act)
debug_unit = psb_get_debug_unit()
debug_level = psb_get_debug_level()
ctxt = desc_a%get_context()
call psb_info(ctxt, me, np)
if (.not.allocated(b%v)) then
info = psb_err_invalid_vect_state_
call psb_errpush(info,name)
goto 9999
endif
if (.not.allocated(x%v)) then
info = psb_err_invalid_vect_state_
call psb_errpush(info,name)
goto 9999
endif
mglob = desc_a%get_global_rows()
n_row = desc_a%get_local_rows()
n_col = desc_a%get_local_cols()
if (present(istop)) then
istop_ = istop
else
istop_ = psb_get_istop_default()
endif
if (.not.psb_is_valid_istop(istop_)) then
info=psb_err_invalid_istop_
err=info
call psb_errpush(info,name,i_err=(/istop_/))
goto 9999
end if
!
! istop_ = 1: normwise backward error, infinity norm
! istop_ = 2: ||r||/||b|| norm 2
!
select case(istop_)
case(psb_istop_ani_,psb_istop_bn2_,&
& psb_istop_rn2_abs_, psb_istop_rrn2_)
! nothing needed
case default
! should never get here
info=psb_err_internal_error_
err=info
call psb_errpush(info,name,a_err="invalid istop_")
goto 9999
end select
call psb_chkvect(mglob,lone,x%get_nrows(),lone,lone,desc_a,info)
if (info == psb_success_)&
& call psb_chkvect(mglob,lone,b%get_nrows(),lone,lone,desc_a,info)
if(info /= psb_success_) then
info=psb_err_from_subroutine_
call psb_errpush(info,name,a_err='psb_chkvect on X/B')
goto 9999
end if
naux=4*n_col
allocate(aux(naux), stat=info)
if (info == psb_success_) call psb_geall(wwrk,desc_a,info,n=9_psb_ipk_)
if (info == psb_success_) call psb_geasb(wwrk,desc_a,info,mold=x%v,scratch=.true.)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
if (present(itmax)) then
itmax_ = itmax
else
itmax_ = 1000
endif
if (present(itrace)) then
itrace_ = itrace
else
itrace_ = 0
end if
y => wwrk(1)
r1 => wwrk(2)
r2 => wwrk(3)
v => wwrk(4)
w => wwrk(5)
w1 => wwrk(6)
w2 => wwrk(7)
wtmp => wwrk(8)
res => wwrk(9)
do_cond = present(cond)
epsmach = epsilon(sone)
! res = b - A*x
call psb_geaxpby(cone,b,czero,res,desc_a,info)
if (info == psb_success_) call psb_spmm(-cone,a,x,cone,res,desc_a,info,work=aux)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
select case(istop_)
case(psb_istop_ani_)
ani = psb_spnrmi(a,desc_a,info)
bni = psb_geamax(b,desc_a,info)
case(psb_istop_bn2_)
bn2 = psb_genrm2(b,desc_a,info)
case(psb_istop_rn2_abs_)
! nothing needed
case(psb_istop_rrn2_)
r0n2 = psb_genrm2(res,desc_a,info)
end select
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
errnum = czero
errden = cone
deps = eps
converged = .false.
if ((itrace_ > 0).and.(me == 0)) call log_header(methdname)
! y = beta1 * P' * v1, with v1 the first Lanczos vector.
call psb_geaxpby(cone,res,czero,y,desc_a,info)
if (info == psb_success_) call psb_geaxpby(cone,res,czero,r1,desc_a,info)
if (info == psb_success_) call prec%apply(res,y,desc_a,info,work=aux)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
beta1 = sqrt(psb_gedot(res,y,desc_a,info))
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
! If beta1 is numerically zero, x is already acceptable.
if (abs(beta1) <= epsmach) then
itx = 0
converged = .true.
if (do_cond) cond = szero
select case(istop_)
case(psb_istop_ani_)
rni = psb_geamax(res,desc_a,info)
xni = psb_geamax(x,desc_a,info)
errnum = rni
errden = ani*xni + bni
case(psb_istop_bn2_)
errnum = abs(beta1)
errden = bn2
case(psb_istop_rn2_abs_)
errnum = abs(beta1)
errden = sone
case(psb_istop_rrn2_)
errnum = abs(beta1)
errden = r0n2
end select
if (errden == szero) errden = sone
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
end if
beta = beta1
oldb = czero
dbar = czero
epsln = czero
phibar = beta1
rhs1 = beta1
rhs2 = czero
cs = -sone
sn = czero
itx = 0
if (do_cond) then
tnorm2 = 0.0_psb_spk_
ynorm2 = 0.0_psb_spk_
gmax = 0.0_psb_spk_
gmin = huge(sone)
end if
call psb_geaxpby(cone,r1,czero,r2,desc_a,info)
if (info == psb_success_) call psb_geaxpby(czero,x,czero,w,desc_a,info)
if (info == psb_success_) call psb_geaxpby(czero,x,czero,w1,desc_a,info)
if (info == psb_success_) call psb_geaxpby(czero,x,czero,w2,desc_a,info)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
if (.not.converged) then
do while (itx < itmax_)
if (abs(beta) <= epsmach) exit
itx = itx + 1
s = cone/beta
call psb_geaxpby(s,y,czero,v,desc_a,info)
if (info == psb_success_) call psb_spmm(cone,a,v,czero,y,desc_a,info,work=aux)
if (itx >= 2 .and. info == psb_success_) then
call psb_geaxpby((-beta/oldb),r1,cone,y,desc_a,info)
end if
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
alfa = psb_gedot(v,y,desc_a,info)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
call psb_geaxpby((-alfa/beta),r2,cone,y,desc_a,info)
if (info == psb_success_) call psb_geaxpby(cone,r2,czero,r1,desc_a,info)
if (info == psb_success_) call psb_geaxpby(cone,y,czero,r2,desc_a,info)
if (info == psb_success_) call prec%apply(r2,y,desc_a,info,work=aux)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
oldb = beta
beta = sqrt(psb_gedot(r2,y,desc_a,info))
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
if (do_cond) then
tnorm2 = tnorm2 + abs(alfa)**2 + abs(oldb)**2 + abs(beta)**2
if (itx == 1) then
gmax = abs(alfa)
gmin = gmax
end if
end if
oldeps = epsln
delta = dbar
gbar = alfa
rotx(1) = delta
roty(1) = gbar
call crot(1,rotx,1,roty,1,cs,sn)
delta = rotx(1)
gbar = -roty(1)
epsln = czero
dbar = beta
rotx(1) = epsln
roty(1) = dbar
call crot(1,rotx,1,roty,1,cs,sn)
epsln = rotx(1)
dbar = -roty(1)
gamma = gbar
betatmp = beta
call crotg(gamma,betatmp,cs,sn)
if (abs(gamma) <= epsmach) exit
phi = phibar
phibar = czero
rotx(1) = phi
roty(1) = phibar
call crot(1,rotx,1,roty,1,cs,-sn)
phi = rotx(1)
phibar = roty(1)
denom = cone/gamma
call psb_geaxpby(cone,w2,czero,w1,desc_a,info)
if (info == psb_success_) call psb_geaxpby(cone,w,czero,w2,desc_a,info)
if (info == psb_success_) call psb_geaxpby(cone,v,czero,wtmp,desc_a,info)
if (info == psb_success_) call psb_geaxpby(-oldeps,w1,cone,wtmp,desc_a,info)
if (info == psb_success_) call psb_geaxpby(-delta,w2,cone,wtmp,desc_a,info)
if (info == psb_success_) call psb_geaxpby(denom,wtmp,czero,w,desc_a,info)
if (info == psb_success_) call psb_geaxpby(phi,w,cone,x,desc_a,info)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
if (do_cond) then
gmax = max(gmax,abs(gamma))
gmin = min(gmin,abs(gamma))
zeta = rhs1/gamma
ynorm2 = ynorm2 + abs(zeta)**2
rhs1 = rhs2 - delta*zeta
rhs2 = -epsln*zeta
end if
select case(istop_)
case(psb_istop_ani_)
! Compute true residual only for the ANI stopping criterion.
call psb_geaxpby(cone,b,czero,res,desc_a,info)
if (info == psb_success_) call psb_spmm(-cone,a,x,cone,res,desc_a,info,work=aux)
if (info == psb_success_) rni = psb_geamax(res,desc_a,info)
if (info == psb_success_) xni = psb_geamax(x,desc_a,info)
errnum = rni
errden = ani*xni + bni
case(psb_istop_bn2_)
errnum = abs(phibar)
errden = bn2
case(psb_istop_rn2_abs_)
errnum = abs(phibar)
errden = sone
case(psb_istop_rrn2_)
errnum = abs(phibar)
errden = r0n2
end select
if (errden == szero) errden = sone
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
if (itrace_ > 0) &
& call log_conv(methdname,me,itx,itrace_,errnum,errden,deps)
if (errnum <= eps*errden) then
converged = .true.
exit
end if
end do
end if
if ((.not.converged) .and. (itx >= itmax_)) then
if (debug_level >= psb_debug_ext_)&
& write(debug_unit,*) me,' ',trim(name),': MINRES reached iteration limit'
end if
if (do_cond) then
if (gmin > 0.0_psb_spk_) then
cond = gmax/gmin
else
cond = huge(sone)
end if
end if
call log_end(methdname,me,itx,itrace_,errnum,errden,deps,err=derr,iter=iter)
if (present(err)) err = derr
if (info == psb_success_) call psb_gefree(wwrk,desc_a,info)
if (info == psb_success_) deallocate(aux,stat=info)
if (info /= psb_success_) then
call psb_errpush(info,name)
goto 9999
end if
call psb_erractionrestore(err_act)
return
9999 call psb_error_handler(err_act)
return
end subroutine psb_cminres_vect

5
linsolve/impl/psb_dkrylov.f90
Unescape Escape View File

@ -150,7 +150,7 @@ Subroutine psb_dkrylov_vect(method,a,prec,b,x,eps,desc_a,info,&
procedure(psb_dkryl_vect) :: psb_dbicg_vect, psb_dcgstab_vect,&
& psb_dcgs_vect
procedure(psb_dkryl_rest_vect) :: psb_drgmres_vect, psb_dcgstabl_vect, psb_dgcr_vect
procedure(psb_dkryl_cond_vect) :: psb_dcg_vect, psb_dfcg_vect
procedure(psb_dkryl_cond_vect) :: psb_dcg_vect, psb_dfcg_vect, psb_dminres_vect
logical :: do_alloc_wrk
type(psb_ctxt_type) :: ctxt
@ -199,6 +199,9 @@ Subroutine psb_dkrylov_vect(method,a,prec,b,x,eps,desc_a,info,&
case('RGMRES','GMRES')
call psb_drgmres_vect(a,prec,b,x,eps,desc_a,info,&
&itmax,iter,err,itrace=itrace_,irst=irst,istop=istop)
case('MINRES','PMINRES')
call psb_dminres_vect(a,prec,b,x,eps,desc_a,info,&
&itmax,iter,err,itrace=itrace_,istop=istop)
case('BICGSTABL')
call psb_dcgstabl_vect(a,prec,b,x,eps,desc_a,info,&
&itmax,iter,err,itrace=itrace_,irst=irst,istop=istop)

526
linsolve/impl/psb_dminres.f90
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@ -0,0 +1,526 @@
!
! 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 prior 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.
!
!
! File: psb_dminres.f90
! CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
! C C
! C References: C
! C [1] Duff, I., Marrone, M., Radicati, G., and Vittoli, C. C
! C Level 3 basic linear algebra subprograms for sparse C
! C matrices: a user level interface C
! C ACM Trans. Math. Softw., 23(3), 379-401, 1997. C
! C C
! C C
! C [2] S. Filippone, M. Colajanni C
! C PSBLAS: A library for parallel linear algebra C
! C computation on sparse matrices C
! C ACM Trans. on Math. Softw., 26(4), 527-550, Dec. 2000. C
! C C
! C [3] M. Arioli, I. Duff, M. Ruiz C
! C Stopping criteria for iterative solvers C
! C SIAM J. Matrix Anal. Appl., Vol. 13, pp. 138-144, 1992 C
! C C
! C C
! C [4] R. Barrett et al C
! C Templates for the solution of linear systems C
! C SIAM, 1993
! C C
! C C
! CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
! File: psb_dminres.f90
!
! Subroutine: psb_dminres
! This subroutine implements the MINRES method.
!
!
! Arguments:
!
! a - type(psb_dspmat_type) Input: sparse matrix containing A.
! prec - class(psb_dprec_type) Input: preconditioner
! b(:) - real Input: vector containing the
! right hand side B
! x(:) - real Input/Output: vector containing the
! initial guess and final solution X.
! eps - real Input: Stopping tolerance; the iteration is
! stopped when the error estimate |err| <= eps
! desc_a - type(psb_desc_type). Input: The communication descriptor.
! info - integer. Output: Return code
!
! itmax - integer(optional) Input: maximum number of iterations to be
! performed.
! iter - integer(optional) Output: how many iterations have been
! performed.
! performed.
! err - real (optional) Output: error estimate on exit. If the
! denominator of the estimate is exactly
! 0, it is changed into 1.
! itrace - integer(optional) Input: print an informational message
! with the error estimate every itrace
! iterations
! istop - integer(optional) Input: stopping criterion, or how
! to estimate the error.
! 1: err = |r|/(|a||x|+|b|); here the iteration is
! stopped when |r| <= eps * (|a||x|+|b|)
! 2: err = |r|/|b|; here the iteration is
! stopped when |r| <= eps * |b|
! where r is the (preconditioned, recursive
! estimate of) residual.
!
!
subroutine psb_dminres_vect(a,prec,b,x,eps,desc_a,info,&
& itmax,iter,err,itrace,istop,cond)
use psb_base_mod
use psb_prec_mod
use psb_d_linsolve_conv_mod
use psb_linsolve_mod
implicit none
type(psb_dspmat_type), intent(in) :: a
Type(psb_desc_type), Intent(in) :: desc_a
class(psb_dprec_type), intent(inout) :: prec
type(psb_d_vect_type), Intent(inout) :: b
type(psb_d_vect_type), Intent(inout) :: x
Real(psb_dpk_), Intent(in) :: eps
integer(psb_ipk_), intent(out) :: info
integer(psb_ipk_), Optional, Intent(in) :: itmax, itrace, istop
integer(psb_ipk_), Optional, Intent(out) :: iter
Real(psb_dpk_), Optional, Intent(out) :: err, cond
! = Local data
real(psb_dpk_), allocatable, target :: aux(:)
type(psb_d_vect_type), allocatable, target :: wwrk(:)
type(psb_d_vect_type), pointer :: y, r1, r2, v, w, w1, w2, wtmp, res
real(psb_dpk_) :: alfa, beta, beta1, dbar, delta, denom
real(psb_dpk_) :: epsln, gamma, gbar, oldb, oldeps, phi, phibar
real(psb_dpk_) :: rhs1, rhs2, s, zeta, betatmp
real(psb_dpk_) :: rotx(1), roty(1)
real(psb_dpk_) :: cs
real(psb_dpk_) :: sn
integer(psb_ipk_) :: itmax_, istop_, naux, itx, itrace_, n_col, n_row, err_act
integer(psb_lpk_) :: mglob
integer(psb_ipk_) :: debug_level, debug_unit
type(psb_ctxt_type) :: ctxt
integer(psb_ipk_) :: np, me
real(psb_dpk_) :: derr, errnum, errden, deps
logical :: do_cond
logical :: converged
real(psb_dpk_) :: epsmach
real(psb_dpk_) :: gmax, gmin, tnorm2, ynorm2
real(psb_dpk_) :: rni, xni, bni, ani, bn2, r0n2
real(psb_dpk_) :: dotv
character(len=20) :: name
character(len=*), parameter :: methdname='MINRES'
info = psb_success_
name = 'psb_dminres'
call psb_erractionsave(err_act)
debug_unit = psb_get_debug_unit()
debug_level = psb_get_debug_level()
ctxt = desc_a%get_context()
call psb_info(ctxt, me, np)
if (.not.allocated(b%v)) then
info = psb_err_invalid_vect_state_
call psb_errpush(info,name)
goto 9999
endif
if (.not.allocated(x%v)) then
info = psb_err_invalid_vect_state_
call psb_errpush(info,name)
goto 9999
endif
mglob = desc_a%get_global_rows()
n_row = desc_a%get_local_rows()
n_col = desc_a%get_local_cols()
if (present(istop)) then
istop_ = istop
else
istop_ = psb_get_istop_default()
endif
if (.not.psb_is_valid_istop(istop_)) then
info=psb_err_invalid_istop_
err=info
call psb_errpush(info,name,i_err=(/istop_/))
goto 9999
end if
!
! istop_ = 1: normwise backward error, infinity norm
! istop_ = 2: ||r||/||b|| norm 2
!
select case(istop_)
case(psb_istop_ani_,psb_istop_bn2_,&
& psb_istop_rn2_abs_, psb_istop_rrn2_)
! nothing needed
case default
! should never get here
info=psb_err_internal_error_
err=info
call psb_errpush(info,name,a_err="invalid istop_")
goto 9999
end select
call psb_chkvect(mglob,lone,x%get_nrows(),lone,lone,desc_a,info)
if (info == psb_success_)&
& call psb_chkvect(mglob,lone,b%get_nrows(),lone,lone,desc_a,info)
if(info /= psb_success_) then
info=psb_err_from_subroutine_
call psb_errpush(info,name,a_err='psb_chkvect on X/B')
goto 9999
end if
naux=4*n_col
allocate(aux(naux), stat=info)
if (info == psb_success_) call psb_geall(wwrk,desc_a,info,n=9_psb_ipk_)
if (info == psb_success_) call psb_geasb(wwrk,desc_a,info,mold=x%v,scratch=.true.)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
if (present(itmax)) then
itmax_ = itmax
else
itmax_ = 1000
endif
if (present(itrace)) then
itrace_ = itrace
else
itrace_ = 0
end if
y => wwrk(1)
r1 => wwrk(2)
r2 => wwrk(3)
v => wwrk(4)
w => wwrk(5)
w1 => wwrk(6)
w2 => wwrk(7)
wtmp => wwrk(8)
res => wwrk(9)
do_cond = present(cond)
epsmach = epsilon(done)
! res = b - A*x
call psb_geaxpby(done,b,dzero,res,desc_a,info)
if (info == psb_success_) call psb_spmm(-done,a,x,done,res,desc_a,info,work=aux)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
select case(istop_)
case(psb_istop_ani_)
ani = psb_spnrmi(a,desc_a,info)
bni = psb_geamax(b,desc_a,info)
case(psb_istop_bn2_)
bn2 = psb_genrm2(b,desc_a,info)
case(psb_istop_rn2_abs_)
! nothing needed
case(psb_istop_rrn2_)
r0n2 = psb_genrm2(res,desc_a,info)
end select
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
errnum = dzero
errden = done
deps = eps
converged = .false.
if ((itrace_ > 0).and.(me == 0)) call log_header(methdname)
! y = beta1 * P' * v1, with v1 the first Lanczos vector.
call psb_geaxpby(done,res,dzero,y,desc_a,info)
if (info == psb_success_) call psb_geaxpby(done,res,dzero,r1,desc_a,info)
if (info == psb_success_) call prec%apply(res,y,desc_a,info,work=aux)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
dotv = psb_gedot(res,y,desc_a,info)
if (dotv < -epsmach*max(done,abs(dotv))) then
info=psb_err_pivot_too_small_
call psb_errpush(info,name,a_err='MINRES breakdown: negative (r,z)')
goto 9999
end if
if (dotv < dzero) dotv = dzero
beta1 = sqrt(dotv)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
! If beta1 is numerically zero, x is already acceptable.
if (abs(beta1) <= epsmach) then
itx = 0
converged = .true.
if (do_cond) cond = dzero
select case(istop_)
case(psb_istop_ani_)
rni = psb_geamax(res,desc_a,info)
xni = psb_geamax(x,desc_a,info)
errnum = rni
errden = ani*xni + bni
case(psb_istop_bn2_)
errnum = abs(beta1)
errden = bn2
case(psb_istop_rn2_abs_)
errnum = abs(beta1)
errden = done
case(psb_istop_rrn2_)
errnum = abs(beta1)
errden = r0n2
end select
if (errden == dzero) errden = done
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
end if
beta = beta1
oldb = dzero
dbar = dzero
epsln = dzero
phibar = beta1
rhs1 = beta1
rhs2 = dzero
cs = -done
sn = dzero
itx = 0
if (do_cond) then
tnorm2 = 0.0_psb_dpk_
ynorm2 = 0.0_psb_dpk_
gmax = 0.0_psb_dpk_
gmin = huge(done)
end if
call psb_geaxpby(done,r1,dzero,r2,desc_a,info)
if (info == psb_success_) call psb_geaxpby(dzero,x,dzero,w,desc_a,info)
if (info == psb_success_) call psb_geaxpby(dzero,x,dzero,w1,desc_a,info)
if (info == psb_success_) call psb_geaxpby(dzero,x,dzero,w2,desc_a,info)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
if (.not.converged) then
do while (itx < itmax_)
if (abs(beta) <= epsmach) exit
itx = itx + 1
s = done/beta
call psb_geaxpby(s,y,dzero,v,desc_a,info)
if (info == psb_success_) call psb_spmm(done,a,v,dzero,y,desc_a,info,work=aux)
if (itx >= 2 .and. info == psb_success_) then
call psb_geaxpby((-beta/oldb),r1,done,y,desc_a,info)
end if
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
alfa = psb_gedot(v,y,desc_a,info)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
call psb_geaxpby((-alfa/beta),r2,done,y,desc_a,info)
if (info == psb_success_) call psb_geaxpby(done,r2,dzero,r1,desc_a,info)
if (info == psb_success_) call psb_geaxpby(done,y,dzero,r2,desc_a,info)
if (info == psb_success_) call prec%apply(r2,y,desc_a,info,work=aux)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
oldb = beta
dotv = psb_gedot(r2,y,desc_a,info)
if (dotv < -epsmach*max(done,abs(dotv))) then
info=psb_err_pivot_too_small_
call psb_errpush(info,name,a_err='MINRES breakdown: negative (r2,z2)')
goto 9999
end if
if (dotv < dzero) dotv = dzero
beta = sqrt(dotv)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
if (do_cond) then
tnorm2 = tnorm2 + abs(alfa)**2 + abs(oldb)**2 + abs(beta)**2
if (itx == 1) then
gmax = abs(alfa)
gmin = gmax
end if
end if
oldeps = epsln
delta = dbar
gbar = alfa
rotx(1) = delta
roty(1) = gbar
call drot(1,rotx,1,roty,1,cs,sn)
delta = rotx(1)
gbar = -roty(1)
epsln = dzero
dbar = beta
rotx(1) = epsln
roty(1) = dbar
call drot(1,rotx,1,roty,1,cs,sn)
epsln = rotx(1)
dbar = -roty(1)
gamma = gbar
betatmp = beta
call drotg(gamma,betatmp,cs,sn)
if (abs(gamma) <= epsmach) exit
phi = phibar
phibar = dzero
rotx(1) = phi
roty(1) = phibar
call drot(1,rotx,1,roty,1,cs,-sn)
phi = rotx(1)
phibar = roty(1)
denom = done/gamma
call psb_geaxpby(done,w2,dzero,w1,desc_a,info)
if (info == psb_success_) call psb_geaxpby(done,w,dzero,w2,desc_a,info)
if (info == psb_success_) call psb_geaxpby(done,v,dzero,wtmp,desc_a,info)
if (info == psb_success_) call psb_geaxpby(-oldeps,w1,done,wtmp,desc_a,info)
if (info == psb_success_) call psb_geaxpby(-delta,w2,done,wtmp,desc_a,info)
if (info == psb_success_) call psb_geaxpby(denom,wtmp,dzero,w,desc_a,info)
if (info == psb_success_) call psb_geaxpby(phi,w,done,x,desc_a,info)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
if (do_cond) then
gmax = max(gmax,abs(gamma))
gmin = min(gmin,abs(gamma))
zeta = rhs1/gamma
ynorm2 = ynorm2 + abs(zeta)**2
rhs1 = rhs2 - delta*zeta
rhs2 = -epsln*zeta
end if
select case(istop_)
case(psb_istop_ani_)
! Compute true residual only for the ANI stopping criterion.
call psb_geaxpby(done,b,dzero,res,desc_a,info)
if (info == psb_success_) call psb_spmm(-done,a,x,done,res,desc_a,info,work=aux)
if (info == psb_success_) rni = psb_geamax(res,desc_a,info)
if (info == psb_success_) xni = psb_geamax(x,desc_a,info)
errnum = rni
errden = ani*xni + bni
case(psb_istop_bn2_)
errnum = abs(phibar)
errden = bn2
case(psb_istop_rn2_abs_)
errnum = abs(phibar)
errden = done
case(psb_istop_rrn2_)
errnum = abs(phibar)
errden = r0n2
end select
if (errden == dzero) errden = done
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
if (itrace_ > 0) &
& call log_conv(methdname,me,itx,itrace_,errnum,errden,deps)
if (errnum <= eps*errden) then
converged = .true.
exit
end if
end do
end if
if ((.not.converged) .and. (itx >= itmax_)) then
if (debug_level >= psb_debug_ext_)&
& write(debug_unit,*) me,' ',trim(name),': MINRES reached iteration limit'
end if
if (do_cond) then
if (gmin > 0.0_psb_dpk_) then
cond = gmax/gmin
else
cond = huge(done)
end if
end if
call log_end(methdname,me,itx,itrace_,errnum,errden,deps,err=derr,iter=iter)
if (present(err)) err = derr
if (info == psb_success_) call psb_gefree(wwrk,desc_a,info)
if (info == psb_success_) deallocate(aux,stat=info)
if (info /= psb_success_) then
call psb_errpush(info,name)
goto 9999
end if
call psb_erractionrestore(err_act)
return
9999 call psb_error_handler(err_act)
return
end subroutine psb_dminres_vect

5
linsolve/impl/psb_skrylov.f90
Unescape Escape View File

@ -150,7 +150,7 @@ Subroutine psb_skrylov_vect(method,a,prec,b,x,eps,desc_a,info,&
procedure(psb_skryl_vect) :: psb_sbicg_vect, psb_scgstab_vect,&
& psb_scgs_vect
procedure(psb_skryl_rest_vect) :: psb_srgmres_vect, psb_scgstabl_vect, psb_sgcr_vect
procedure(psb_skryl_cond_vect) :: psb_scg_vect, psb_sfcg_vect
procedure(psb_skryl_cond_vect) :: psb_scg_vect, psb_sfcg_vect, psb_sminres_vect
logical :: do_alloc_wrk
type(psb_ctxt_type) :: ctxt
@ -199,6 +199,9 @@ Subroutine psb_skrylov_vect(method,a,prec,b,x,eps,desc_a,info,&
case('RGMRES','GMRES')
call psb_srgmres_vect(a,prec,b,x,eps,desc_a,info,&
&itmax,iter,err,itrace=itrace_,irst=irst,istop=istop)
case('MINRES','PMINRES')
call psb_sminres_vect(a,prec,b,x,eps,desc_a,info,&
&itmax,iter,err,itrace=itrace_,istop=istop)
case('BICGSTABL')
call psb_scgstabl_vect(a,prec,b,x,eps,desc_a,info,&
&itmax,iter,err,itrace=itrace_,irst=irst,istop=istop)

526
linsolve/impl/psb_sminres.f90
Unescape Escape View File

@ -0,0 +1,526 @@
!
! 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 prior 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.
!
!
! File: psb_sminres.f90
! CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
! C C
! C References: C
! C [1] Duff, I., Marrone, M., Radicati, G., and Vittoli, C. C
! C Level 3 basic linear algebra subprograms for sparse C
! C matrices: a user level interface C
! C ACM Trans. Math. Softw., 23(3), 379-401, 1997. C
! C C
! C C
! C [2] S. Filippone, M. Colajanni C
! C PSBLAS: A library for parallel linear algebra C
! C computation on sparse matrices C
! C ACM Trans. on Math. Softw., 26(4), 527-550, Dec. 2000. C
! C C
! C [3] M. Arioli, I. Duff, M. Ruiz C
! C Stopping criteria for iterative solvers C
! C SIAM J. Matrix Anal. Appl., Vol. 13, pp. 138-144, 1992 C
! C C
! C C
! C [4] R. Barrett et al C
! C Templates for the solution of linear systems C
! C SIAM, 1993
! C C
! C C
! CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
! File: psb_sminres.f90
!
! Subroutine: psb_sminres
! This subroutine implements the MINRES method.
!
!
! Arguments:
!
! a - type(psb_sspmat_type) Input: sparse matrix containing A.
! prec - class(psb_sprec_type) Input: preconditioner
! b(:) - real Input: vector containing the
! right hand side B
! x(:) - real Input/Output: vector containing the
! initial guess and final solution X.
! eps - real Input: Stopping tolerance; the iteration is
! stopped when the error estimate |err| <= eps
! desc_a - type(psb_desc_type). Input: The communication descriptor.
! info - integer. Output: Return code
!
! itmax - integer(optional) Input: maximum number of iterations to be
! performed.
! iter - integer(optional) Output: how many iterations have been
! performed.
! performed.
! err - real (optional) Output: error estimate on exit. If the
! denominator of the estimate is exactly
! 0, it is changed into 1.
! itrace - integer(optional) Input: print an informational message
! with the error estimate every itrace
! iterations
! istop - integer(optional) Input: stopping criterion, or how
! to estimate the error.
! 1: err = |r|/(|a||x|+|b|); here the iteration is
! stopped when |r| <= eps * (|a||x|+|b|)
! 2: err = |r|/|b|; here the iteration is
! stopped when |r| <= eps * |b|
! where r is the (preconditioned, recursive
! estimate of) residual.
!
!
subroutine psb_sminres_vect(a,prec,b,x,eps,desc_a,info,&
& itmax,iter,err,itrace,istop,cond)
use psb_base_mod
use psb_prec_mod
use psb_s_linsolve_conv_mod
use psb_linsolve_mod
implicit none
type(psb_sspmat_type), intent(in) :: a
Type(psb_desc_type), Intent(in) :: desc_a
class(psb_sprec_type), intent(inout) :: prec
type(psb_s_vect_type), Intent(inout) :: b
type(psb_s_vect_type), Intent(inout) :: x
Real(psb_spk_), Intent(in) :: eps
integer(psb_ipk_), intent(out) :: info
integer(psb_ipk_), Optional, Intent(in) :: itmax, itrace, istop
integer(psb_ipk_), Optional, Intent(out) :: iter
Real(psb_spk_), Optional, Intent(out) :: err, cond
! = Local data
real(psb_spk_), allocatable, target :: aux(:)
type(psb_s_vect_type), allocatable, target :: wwrk(:)
type(psb_s_vect_type), pointer :: y, r1, r2, v, w, w1, w2, wtmp, res
real(psb_spk_) :: alfa, beta, beta1, dbar, delta, denom
real(psb_spk_) :: epsln, gamma, gbar, oldb, oldeps, phi, phibar
real(psb_spk_) :: rhs1, rhs2, s, zeta, betatmp
real(psb_spk_) :: rotx(1), roty(1)
real(psb_spk_) :: cs
real(psb_spk_) :: sn
integer(psb_ipk_) :: itmax_, istop_, naux, itx, itrace_, n_col, n_row, err_act
integer(psb_lpk_) :: mglob
integer(psb_ipk_) :: debug_level, debug_unit
type(psb_ctxt_type) :: ctxt
integer(psb_ipk_) :: np, me
real(psb_dpk_) :: derr, errnum, errden, deps
logical :: do_cond
logical :: converged
real(psb_spk_) :: epsmach
real(psb_spk_) :: gmax, gmin, tnorm2, ynorm2
real(psb_spk_) :: rni, xni, bni, ani, bn2, r0n2
real(psb_spk_) :: dotv
character(len=20) :: name
character(len=*), parameter :: methdname='MINRES'
info = psb_success_
name = 'psb_sminres'
call psb_erractionsave(err_act)
debug_unit = psb_get_debug_unit()
debug_level = psb_get_debug_level()
ctxt = desc_a%get_context()
call psb_info(ctxt, me, np)
if (.not.allocated(b%v)) then
info = psb_err_invalid_vect_state_
call psb_errpush(info,name)
goto 9999
endif
if (.not.allocated(x%v)) then
info = psb_err_invalid_vect_state_
call psb_errpush(info,name)
goto 9999
endif
mglob = desc_a%get_global_rows()
n_row = desc_a%get_local_rows()
n_col = desc_a%get_local_cols()
if (present(istop)) then
istop_ = istop
else
istop_ = psb_get_istop_default()
endif
if (.not.psb_is_valid_istop(istop_)) then
info=psb_err_invalid_istop_
err=info
call psb_errpush(info,name,i_err=(/istop_/))
goto 9999
end if
!
! istop_ = 1: normwise backward error, infinity norm
! istop_ = 2: ||r||/||b|| norm 2
!
select case(istop_)
case(psb_istop_ani_,psb_istop_bn2_,&
& psb_istop_rn2_abs_, psb_istop_rrn2_)
! nothing needed
case default
! should never get here
info=psb_err_internal_error_
err=info
call psb_errpush(info,name,a_err="invalid istop_")
goto 9999
end select
call psb_chkvect(mglob,lone,x%get_nrows(),lone,lone,desc_a,info)
if (info == psb_success_)&
& call psb_chkvect(mglob,lone,b%get_nrows(),lone,lone,desc_a,info)
if(info /= psb_success_) then
info=psb_err_from_subroutine_
call psb_errpush(info,name,a_err='psb_chkvect on X/B')
goto 9999
end if
naux=4*n_col
allocate(aux(naux), stat=info)
if (info == psb_success_) call psb_geall(wwrk,desc_a,info,n=9_psb_ipk_)
if (info == psb_success_) call psb_geasb(wwrk,desc_a,info,mold=x%v,scratch=.true.)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
if (present(itmax)) then
itmax_ = itmax
else
itmax_ = 1000
endif
if (present(itrace)) then
itrace_ = itrace
else
itrace_ = 0
end if
y => wwrk(1)
r1 => wwrk(2)
r2 => wwrk(3)
v => wwrk(4)
w => wwrk(5)
w1 => wwrk(6)
w2 => wwrk(7)
wtmp => wwrk(8)
res => wwrk(9)
do_cond = present(cond)
epsmach = epsilon(sone)
! res = b - A*x
call psb_geaxpby(sone,b,szero,res,desc_a,info)
if (info == psb_success_) call psb_spmm(-sone,a,x,sone,res,desc_a,info,work=aux)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
select case(istop_)
case(psb_istop_ani_)
ani = psb_spnrmi(a,desc_a,info)
bni = psb_geamax(b,desc_a,info)
case(psb_istop_bn2_)
bn2 = psb_genrm2(b,desc_a,info)
case(psb_istop_rn2_abs_)
! nothing needed
case(psb_istop_rrn2_)
r0n2 = psb_genrm2(res,desc_a,info)
end select
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
errnum = szero
errden = sone
deps = eps
converged = .false.
if ((itrace_ > 0).and.(me == 0)) call log_header(methdname)
! y = beta1 * P' * v1, with v1 the first Lanczos vector.
call psb_geaxpby(sone,res,szero,y,desc_a,info)
if (info == psb_success_) call psb_geaxpby(sone,res,szero,r1,desc_a,info)
if (info == psb_success_) call prec%apply(res,y,desc_a,info,work=aux)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
dotv = psb_gedot(res,y,desc_a,info)
if (dotv < -epsmach*max(sone,abs(dotv))) then
info=psb_err_pivot_too_small_
call psb_errpush(info,name,a_err='MINRES breakdown: negative (r,z)')
goto 9999
end if
if (dotv < szero) dotv = szero
beta1 = sqrt(dotv)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
! If beta1 is numerically zero, x is already acceptable.
if (abs(beta1) <= epsmach) then
itx = 0
converged = .true.
if (do_cond) cond = szero
select case(istop_)
case(psb_istop_ani_)
rni = psb_geamax(res,desc_a,info)
xni = psb_geamax(x,desc_a,info)
errnum = rni
errden = ani*xni + bni
case(psb_istop_bn2_)
errnum = abs(beta1)
errden = bn2
case(psb_istop_rn2_abs_)
errnum = abs(beta1)
errden = sone
case(psb_istop_rrn2_)
errnum = abs(beta1)
errden = r0n2
end select
if (errden == szero) errden = sone
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
end if
beta = beta1
oldb = szero
dbar = szero
epsln = szero
phibar = beta1
rhs1 = beta1
rhs2 = szero
cs = -sone
sn = szero
itx = 0
if (do_cond) then
tnorm2 = 0.0_psb_spk_
ynorm2 = 0.0_psb_spk_
gmax = 0.0_psb_spk_
gmin = huge(sone)
end if
call psb_geaxpby(sone,r1,szero,r2,desc_a,info)
if (info == psb_success_) call psb_geaxpby(szero,x,szero,w,desc_a,info)
if (info == psb_success_) call psb_geaxpby(szero,x,szero,w1,desc_a,info)
if (info == psb_success_) call psb_geaxpby(szero,x,szero,w2,desc_a,info)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
if (.not.converged) then
do while (itx < itmax_)
if (abs(beta) <= epsmach) exit
itx = itx + 1
s = sone/beta
call psb_geaxpby(s,y,szero,v,desc_a,info)
if (info == psb_success_) call psb_spmm(sone,a,v,szero,y,desc_a,info,work=aux)
if (itx >= 2 .and. info == psb_success_) then
call psb_geaxpby((-beta/oldb),r1,sone,y,desc_a,info)
end if
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
alfa = psb_gedot(v,y,desc_a,info)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
call psb_geaxpby((-alfa/beta),r2,sone,y,desc_a,info)
if (info == psb_success_) call psb_geaxpby(sone,r2,szero,r1,desc_a,info)
if (info == psb_success_) call psb_geaxpby(sone,y,szero,r2,desc_a,info)
if (info == psb_success_) call prec%apply(r2,y,desc_a,info,work=aux)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
oldb = beta
dotv = psb_gedot(r2,y,desc_a,info)
if (dotv < -epsmach*max(sone,abs(dotv))) then
info=psb_err_pivot_too_small_
call psb_errpush(info,name,a_err='MINRES breakdown: negative (r2,z2)')
goto 9999
end if
if (dotv < szero) dotv = szero
beta = sqrt(dotv)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
if (do_cond) then
tnorm2 = tnorm2 + abs(alfa)**2 + abs(oldb)**2 + abs(beta)**2
if (itx == 1) then
gmax = abs(alfa)
gmin = gmax
end if
end if
oldeps = epsln
delta = dbar
gbar = alfa
rotx(1) = delta
roty(1) = gbar
call srot(1,rotx,1,roty,1,cs,sn)
delta = rotx(1)
gbar = -roty(1)
epsln = szero
dbar = beta
rotx(1) = epsln
roty(1) = dbar
call srot(1,rotx,1,roty,1,cs,sn)
epsln = rotx(1)
dbar = -roty(1)
gamma = gbar
betatmp = beta
call srotg(gamma,betatmp,cs,sn)
if (abs(gamma) <= epsmach) exit
phi = phibar
phibar = szero
rotx(1) = phi
roty(1) = phibar
call srot(1,rotx,1,roty,1,cs,-sn)
phi = rotx(1)
phibar = roty(1)
denom = sone/gamma
call psb_geaxpby(sone,w2,szero,w1,desc_a,info)
if (info == psb_success_) call psb_geaxpby(sone,w,szero,w2,desc_a,info)
if (info == psb_success_) call psb_geaxpby(sone,v,szero,wtmp,desc_a,info)
if (info == psb_success_) call psb_geaxpby(-oldeps,w1,sone,wtmp,desc_a,info)
if (info == psb_success_) call psb_geaxpby(-delta,w2,sone,wtmp,desc_a,info)
if (info == psb_success_) call psb_geaxpby(denom,wtmp,szero,w,desc_a,info)
if (info == psb_success_) call psb_geaxpby(phi,w,sone,x,desc_a,info)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
if (do_cond) then
gmax = max(gmax,abs(gamma))
gmin = min(gmin,abs(gamma))
zeta = rhs1/gamma
ynorm2 = ynorm2 + abs(zeta)**2
rhs1 = rhs2 - delta*zeta
rhs2 = -epsln*zeta
end if
select case(istop_)
case(psb_istop_ani_)
! Compute true residual only for the ANI stopping criterion.
call psb_geaxpby(sone,b,szero,res,desc_a,info)
if (info == psb_success_) call psb_spmm(-sone,a,x,sone,res,desc_a,info,work=aux)
if (info == psb_success_) rni = psb_geamax(res,desc_a,info)
if (info == psb_success_) xni = psb_geamax(x,desc_a,info)
errnum = rni
errden = ani*xni + bni
case(psb_istop_bn2_)
errnum = abs(phibar)
errden = bn2
case(psb_istop_rn2_abs_)
errnum = abs(phibar)
errden = sone
case(psb_istop_rrn2_)
errnum = abs(phibar)
errden = r0n2
end select
if (errden == szero) errden = sone
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
if (itrace_ > 0) &
& call log_conv(methdname,me,itx,itrace_,errnum,errden,deps)
if (errnum <= eps*errden) then
converged = .true.
exit
end if
end do
end if
if ((.not.converged) .and. (itx >= itmax_)) then
if (debug_level >= psb_debug_ext_)&
& write(debug_unit,*) me,' ',trim(name),': MINRES reached iteration limit'
end if
if (do_cond) then
if (gmin > 0.0_psb_spk_) then
cond = gmax/gmin
else
cond = huge(sone)
end if
end if
call log_end(methdname,me,itx,itrace_,errnum,errden,deps,err=derr,iter=iter)
if (present(err)) err = derr
if (info == psb_success_) call psb_gefree(wwrk,desc_a,info)
if (info == psb_success_) deallocate(aux,stat=info)
if (info /= psb_success_) then
call psb_errpush(info,name)
goto 9999
end if
call psb_erractionrestore(err_act)
return
9999 call psb_error_handler(err_act)
return
end subroutine psb_sminres_vect

5
linsolve/impl/psb_zkrylov.f90
Unescape Escape View File

@ -150,7 +150,7 @@ Subroutine psb_zkrylov_vect(method,a,prec,b,x,eps,desc_a,info,&
procedure(psb_zkryl_vect) :: psb_zbicg_vect, psb_zcgstab_vect,&
& psb_zcgs_vect
procedure(psb_zkryl_rest_vect) :: psb_zrgmres_vect, psb_zcgstabl_vect, psb_zgcr_vect
procedure(psb_zkryl_cond_vect) :: psb_zcg_vect, psb_zfcg_vect
procedure(psb_zkryl_cond_vect) :: psb_zcg_vect, psb_zfcg_vect, psb_zminres_vect
logical :: do_alloc_wrk
type(psb_ctxt_type) :: ctxt
@ -199,6 +199,9 @@ Subroutine psb_zkrylov_vect(method,a,prec,b,x,eps,desc_a,info,&
case('RGMRES','GMRES')
call psb_zrgmres_vect(a,prec,b,x,eps,desc_a,info,&
&itmax,iter,err,itrace=itrace_,irst=irst,istop=istop)
case('MINRES','PMINRES')
call psb_zminres_vect(a,prec,b,x,eps,desc_a,info,&
&itmax,iter,err,itrace=itrace_,istop=istop)
case('BICGSTABL')
call psb_zcgstabl_vect(a,prec,b,x,eps,desc_a,info,&
&itmax,iter,err,itrace=itrace_,irst=irst,istop=istop)

511
linsolve/impl/psb_zminres.f90
Unescape Escape View File

@ -0,0 +1,511 @@
!
! 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 prior 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.
!
!
! File: psb_zminres.f90
! CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
! C C
! C References: C
! C [1] Duff, I., Marrone, M., Radicati, G., and Vittoli, C. C
! C Level 3 basic linear algebra subprograms for sparse C
! C matrices: a user level interface C
! C ACM Trans. Math. Softw., 23(3), 379-401, 1997. C
! C C
! C C
! C [2] S. Filippone, M. Colajanni C
! C PSBLAS: A library for parallel linear algebra C
! C computation on sparse matrices C
! C ACM Trans. on Math. Softw., 26(4), 527-550, Dec. 2000. C
! C C
! C [3] M. Arioli, I. Duff, M. Ruiz C
! C Stopping criteria for iterative solvers C
! C SIAM J. Matrix Anal. Appl., Vol. 13, pp. 138-144, 1992 C
! C C
! C C
! C [4] R. Barrett et al C
! C Templates for the solution of linear systems C
! C SIAM, 1993
! C C
! C C
! CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
! File: psb_zminres.f90
!
! Subroutine: psb_zminres
! This subroutine implements the MINRES method.
!
!
! Arguments:
!
! a - type(psb_zspmat_type) Input: sparse matrix containing A.
! prec - class(psb_zprec_type) Input: preconditioner
! b(:) - complex Input: vector containing the
! right hand side B
! x(:) - complex Input/Output: vector containing the
! initial guess and final solution X.
! eps - real Input: Stopping tolerance; the iteration is
! stopped when the error estimate |err| <= eps
! desc_a - type(psb_desc_type). Input: The communication descriptor.
! info - integer. Output: Return code
!
! itmax - integer(optional) Input: maximum number of iterations to be
! performed.
! iter - integer(optional) Output: how many iterations have been
! performed.
! performed.
! err - real (optional) Output: error estimate on exit. If the
! denominator of the estimate is exactly
! 0, it is changed into 1.
! itrace - integer(optional) Input: print an informational message
! with the error estimate every itrace
! iterations
! istop - integer(optional) Input: stopping criterion, or how
! to estimate the error.
! 1: err = |r|/(|a||x|+|b|); here the iteration is
! stopped when |r| <= eps * (|a||x|+|b|)
! 2: err = |r|/|b|; here the iteration is
! stopped when |r| <= eps * |b|
! where r is the (preconditioned, recursive
! estimate of) residual.
!
!
subroutine psb_zminres_vect(a,prec,b,x,eps,desc_a,info,&
& itmax,iter,err,itrace,istop,cond)
use psb_base_mod
use psb_prec_mod
use psb_z_linsolve_conv_mod
use psb_linsolve_mod
implicit none
type(psb_zspmat_type), intent(in) :: a
Type(psb_desc_type), Intent(in) :: desc_a
class(psb_zprec_type), intent(inout) :: prec
type(psb_z_vect_type), Intent(inout) :: b
type(psb_z_vect_type), Intent(inout) :: x
Real(psb_dpk_), Intent(in) :: eps
integer(psb_ipk_), intent(out) :: info
integer(psb_ipk_), Optional, Intent(in) :: itmax, itrace, istop
integer(psb_ipk_), Optional, Intent(out) :: iter
Real(psb_dpk_), Optional, Intent(out) :: err, cond
! = Local data
complex(psb_dpk_), allocatable, target :: aux(:)
type(psb_z_vect_type), allocatable, target :: wwrk(:)
type(psb_z_vect_type), pointer :: y, r1, r2, v, w, w1, w2, wtmp, res
complex(psb_dpk_) :: alfa, beta, beta1, dbar, delta, denom
complex(psb_dpk_) :: epsln, gamma, gbar, oldb, oldeps, phi, phibar
complex(psb_dpk_) :: rhs1, rhs2, s, zeta, betatmp
complex(psb_dpk_) :: rotx(1), roty(1)
real(psb_dpk_) :: cs
complex(psb_dpk_) :: sn
integer(psb_ipk_) :: itmax_, istop_, naux, itx, itrace_, n_col, n_row, err_act
integer(psb_lpk_) :: mglob
integer(psb_ipk_) :: debug_level, debug_unit
type(psb_ctxt_type) :: ctxt
integer(psb_ipk_) :: np, me
real(psb_dpk_) :: derr, errnum, errden, deps
logical :: do_cond
logical :: converged
real(psb_dpk_) :: epsmach
real(psb_dpk_) :: gmax, gmin, tnorm2, ynorm2
real(psb_dpk_) :: rni, xni, bni, ani, bn2, r0n2
character(len=20) :: name
character(len=*), parameter :: methdname='MINRES'
info = psb_success_
name = 'psb_zminres'
call psb_erractionsave(err_act)
debug_unit = psb_get_debug_unit()
debug_level = psb_get_debug_level()
ctxt = desc_a%get_context()
call psb_info(ctxt, me, np)
if (.not.allocated(b%v)) then
info = psb_err_invalid_vect_state_
call psb_errpush(info,name)
goto 9999
endif
if (.not.allocated(x%v)) then
info = psb_err_invalid_vect_state_
call psb_errpush(info,name)
goto 9999
endif
mglob = desc_a%get_global_rows()
n_row = desc_a%get_local_rows()
n_col = desc_a%get_local_cols()
if (present(istop)) then
istop_ = istop
else
istop_ = psb_get_istop_default()
endif
if (.not.psb_is_valid_istop(istop_)) then
info=psb_err_invalid_istop_
err=info
call psb_errpush(info,name,i_err=(/istop_/))
goto 9999
end if
!
! istop_ = 1: normwise backward error, infinity norm
! istop_ = 2: ||r||/||b|| norm 2
!
select case(istop_)
case(psb_istop_ani_,psb_istop_bn2_,&
& psb_istop_rn2_abs_, psb_istop_rrn2_)
! nothing needed
case default
! should never get here
info=psb_err_internal_error_
err=info
call psb_errpush(info,name,a_err="invalid istop_")
goto 9999
end select
call psb_chkvect(mglob,lone,x%get_nrows(),lone,lone,desc_a,info)
if (info == psb_success_)&
& call psb_chkvect(mglob,lone,b%get_nrows(),lone,lone,desc_a,info)
if(info /= psb_success_) then
info=psb_err_from_subroutine_
call psb_errpush(info,name,a_err='psb_chkvect on X/B')
goto 9999
end if
naux=4*n_col
allocate(aux(naux), stat=info)
if (info == psb_success_) call psb_geall(wwrk,desc_a,info,n=9_psb_ipk_)
if (info == psb_success_) call psb_geasb(wwrk,desc_a,info,mold=x%v,scratch=.true.)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
if (present(itmax)) then
itmax_ = itmax
else
itmax_ = 1000
endif
if (present(itrace)) then
itrace_ = itrace
else
itrace_ = 0
end if
y => wwrk(1)
r1 => wwrk(2)
r2 => wwrk(3)
v => wwrk(4)
w => wwrk(5)
w1 => wwrk(6)
w2 => wwrk(7)
wtmp => wwrk(8)
res => wwrk(9)
do_cond = present(cond)
epsmach = epsilon(done)
! res = b - A*x
call psb_geaxpby(zone,b,zzero,res,desc_a,info)
if (info == psb_success_) call psb_spmm(-zone,a,x,zone,res,desc_a,info,work=aux)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
select case(istop_)
case(psb_istop_ani_)
ani = psb_spnrmi(a,desc_a,info)
bni = psb_geamax(b,desc_a,info)
case(psb_istop_bn2_)
bn2 = psb_genrm2(b,desc_a,info)
case(psb_istop_rn2_abs_)
! nothing needed
case(psb_istop_rrn2_)
r0n2 = psb_genrm2(res,desc_a,info)
end select
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
errnum = zzero
errden = zone
deps = eps
converged = .false.
if ((itrace_ > 0).and.(me == 0)) call log_header(methdname)
! y = beta1 * P' * v1, with v1 the first Lanczos vector.
call psb_geaxpby(zone,res,zzero,y,desc_a,info)
if (info == psb_success_) call psb_geaxpby(zone,res,zzero,r1,desc_a,info)
if (info == psb_success_) call prec%apply(res,y,desc_a,info,work=aux)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
beta1 = sqrt(psb_gedot(res,y,desc_a,info))
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
! If beta1 is numerically zero, x is already acceptable.
if (abs(beta1) <= epsmach) then
itx = 0
converged = .true.
if (do_cond) cond = dzero
select case(istop_)
case(psb_istop_ani_)
rni = psb_geamax(res,desc_a,info)
xni = psb_geamax(x,desc_a,info)
errnum = rni
errden = ani*xni + bni
case(psb_istop_bn2_)
errnum = abs(beta1)
errden = bn2
case(psb_istop_rn2_abs_)
errnum = abs(beta1)
errden = done
case(psb_istop_rrn2_)
errnum = abs(beta1)
errden = r0n2
end select
if (errden == dzero) errden = done
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
end if
beta = beta1
oldb = zzero
dbar = zzero
epsln = zzero
phibar = beta1
rhs1 = beta1
rhs2 = zzero
cs = -done
sn = zzero
itx = 0
if (do_cond) then
tnorm2 = 0.0_psb_dpk_
ynorm2 = 0.0_psb_dpk_
gmax = 0.0_psb_dpk_
gmin = huge(done)
end if
call psb_geaxpby(zone,r1,zzero,r2,desc_a,info)
if (info == psb_success_) call psb_geaxpby(zzero,x,zzero,w,desc_a,info)
if (info == psb_success_) call psb_geaxpby(zzero,x,zzero,w1,desc_a,info)
if (info == psb_success_) call psb_geaxpby(zzero,x,zzero,w2,desc_a,info)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
if (.not.converged) then
do while (itx < itmax_)
if (abs(beta) <= epsmach) exit
itx = itx + 1
s = zone/beta
call psb_geaxpby(s,y,zzero,v,desc_a,info)
if (info == psb_success_) call psb_spmm(zone,a,v,zzero,y,desc_a,info,work=aux)
if (itx >= 2 .and. info == psb_success_) then
call psb_geaxpby((-beta/oldb),r1,zone,y,desc_a,info)
end if
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
alfa = psb_gedot(v,y,desc_a,info)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
call psb_geaxpby((-alfa/beta),r2,zone,y,desc_a,info)
if (info == psb_success_) call psb_geaxpby(zone,r2,zzero,r1,desc_a,info)
if (info == psb_success_) call psb_geaxpby(zone,y,zzero,r2,desc_a,info)
if (info == psb_success_) call prec%apply(r2,y,desc_a,info,work=aux)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
oldb = beta
beta = sqrt(psb_gedot(r2,y,desc_a,info))
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
if (do_cond) then
tnorm2 = tnorm2 + abs(alfa)**2 + abs(oldb)**2 + abs(beta)**2
if (itx == 1) then
gmax = abs(alfa)
gmin = gmax
end if
end if
oldeps = epsln
delta = dbar
gbar = alfa
rotx(1) = delta
roty(1) = gbar
call zrot(1,rotx,1,roty,1,cs,sn)
delta = rotx(1)
gbar = -roty(1)
epsln = zzero
dbar = beta
rotx(1) = epsln
roty(1) = dbar
call zrot(1,rotx,1,roty,1,cs,sn)
epsln = rotx(1)
dbar = -roty(1)
gamma = gbar
betatmp = beta
call zrotg(gamma,betatmp,cs,sn)
if (abs(gamma) <= epsmach) exit
phi = phibar
phibar = zzero
rotx(1) = phi
roty(1) = phibar
call zrot(1,rotx,1,roty,1,cs,-sn)
phi = rotx(1)
phibar = roty(1)
denom = zone/gamma
call psb_geaxpby(zone,w2,zzero,w1,desc_a,info)
if (info == psb_success_) call psb_geaxpby(zone,w,zzero,w2,desc_a,info)
if (info == psb_success_) call psb_geaxpby(zone,v,zzero,wtmp,desc_a,info)
if (info == psb_success_) call psb_geaxpby(-oldeps,w1,zone,wtmp,desc_a,info)
if (info == psb_success_) call psb_geaxpby(-delta,w2,zone,wtmp,desc_a,info)
if (info == psb_success_) call psb_geaxpby(denom,wtmp,zzero,w,desc_a,info)
if (info == psb_success_) call psb_geaxpby(phi,w,zone,x,desc_a,info)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
if (do_cond) then
gmax = max(gmax,abs(gamma))
gmin = min(gmin,abs(gamma))
zeta = rhs1/gamma
ynorm2 = ynorm2 + abs(zeta)**2
rhs1 = rhs2 - delta*zeta
rhs2 = -epsln*zeta
end if
select case(istop_)
case(psb_istop_ani_)
! Compute true residual only for the ANI stopping criterion.
call psb_geaxpby(zone,b,zzero,res,desc_a,info)
if (info == psb_success_) call psb_spmm(-zone,a,x,zone,res,desc_a,info,work=aux)
if (info == psb_success_) rni = psb_geamax(res,desc_a,info)
if (info == psb_success_) xni = psb_geamax(x,desc_a,info)
errnum = rni
errden = ani*xni + bni
case(psb_istop_bn2_)
errnum = abs(phibar)
errden = bn2
case(psb_istop_rn2_abs_)
errnum = abs(phibar)
errden = done
case(psb_istop_rrn2_)
errnum = abs(phibar)
errden = r0n2
end select
if (errden == dzero) errden = done
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
if (itrace_ > 0) &
& call log_conv(methdname,me,itx,itrace_,errnum,errden,deps)
if (errnum <= eps*errden) then
converged = .true.
exit
end if
end do
end if
if ((.not.converged) .and. (itx >= itmax_)) then
if (debug_level >= psb_debug_ext_)&
& write(debug_unit,*) me,' ',trim(name),': MINRES reached iteration limit'
end if
if (do_cond) then
if (gmin > 0.0_psb_dpk_) then
cond = gmax/gmin
else
cond = huge(done)
end if
end if
call log_end(methdname,me,itx,itrace_,errnum,errden,deps,err=derr,iter=iter)
if (present(err)) err = derr
if (info == psb_success_) call psb_gefree(wwrk,desc_a,info)
if (info == psb_success_) deallocate(aux,stat=info)
if (info /= psb_success_) then
call psb_errpush(info,name)
goto 9999
end if
call psb_erractionrestore(err_act)
return
9999 call psb_error_handler(err_act)
return
end subroutine psb_zminres_vect

2
test/pdegen/psb_d_pde2d.F90
Unescape Escape View File

@ -778,7 +778,7 @@ program psb_d_pde2d
& desc_a,info,itmax=itmax,iter=iter,&
& err=err,itrace=itrace,&
& istop=istopc)
case('BICGSTAB','BICGSTABL','BICG','CG','CGS','FCG','GCR','RGMRES')
case('BICGSTAB','BICGSTABL','BICG','CG','CGS','FCG','GCR','RGMRES','MINRES')
call psb_krylov(kmethd,a,prec,bv,xxv,eps,&
& desc_a,info,itmax=itmax,iter=iter,err=err,itrace=itrace,&
& istop=istopc,irst=irst)

2
test/pdegen/psb_d_pde3d.F90
Unescape Escape View File

@ -834,7 +834,7 @@ program psb_d_pde3d
& desc_a,info,itmax=itmax,iter=iter,&
& err=err,itrace=itrace,&
& istop=istopc)
case('BICGSTAB','BICGSTABL','BICG','CG','CGS','FCG','GCR','RGMRES')
case('BICGSTAB','BICGSTABL','BICG','CG','CGS','FCG','GCR','RGMRES','MINRES')
call psb_krylov(kmethd,a,prec,bv,xxv,eps,&
& desc_a,info,itmax=itmax,iter=iter,err=err,itrace=itrace,&
& istop=istopc,irst=irst)

2
test/pdegen/psb_s_pde2d.F90
Unescape Escape View File

@ -778,7 +778,7 @@ program psb_s_pde2d
& desc_a,info,itmax=itmax,iter=iter,&
& err=err,itrace=itrace,&
& istop=istopc)
case('BICGSTAB','BICGSTABL','BICG','CG','CGS','FCG','GCR','RGMRES')
case('BICGSTAB','BICGSTABL','BICG','CG','CGS','FCG','GCR','RGMRES','MINRES')
call psb_krylov(kmethd,a,prec,bv,xxv,eps,&
& desc_a,info,itmax=itmax,iter=iter,err=err,itrace=itrace,&
& istop=istopc,irst=irst)

2
test/pdegen/psb_s_pde3d.F90
Unescape Escape View File

@ -834,7 +834,7 @@ program psb_s_pde3d
& desc_a,info,itmax=itmax,iter=iter,&
& err=err,itrace=itrace,&
& istop=istopc)
case('BICGSTAB','BICGSTABL','BICG','CG','CGS','FCG','GCR','RGMRES')
case('BICGSTAB','BICGSTABL','BICG','CG','CGS','FCG','GCR','RGMRES','MINRES')
call psb_krylov(kmethd,a,prec,bv,xxv,eps,&
& desc_a,info,itmax=itmax,iter=iter,err=err,itrace=itrace,&
& istop=istopc,irst=irst)

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