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psblas3/krylov/psb_ccgs.f90

331 lines
13 KiB
Fortran

!!$
!!$ Parallel Sparse BLAS version 3.1
!!$ (C) Copyright 2006, 2007, 2008, 2009, 2010, 2012, 2013
!!$ Salvatore Filippone University of Rome Tor Vergata
!!$ Alfredo Buttari CNRS-IRIT, Toulouse
!!$
!!$ 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.
!!$
!!$
!!$ 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_ccgs.f90
!
! Subroutine: psb_ccgs
! Implements the Conjugate Gradient Squared method.
!
! Arguments:
!
! a - type(psb_cspmat_type) Input: sparse matrix containing A.
! prec - class(psb_cprec_type) Input: preconditioner
! b - complex,dimension(:) Input: vector containing the
! right hand side B
! x - complex,dimension(:) 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_ccgs_vect(a,prec,b,x,eps,desc_a,info,&
& itmax,iter,err,itrace,istop)
use psb_base_mod
use psb_prec_mod
use psb_c_krylov_conv_mod
use psb_krylov_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
! = local data
complex(psb_spk_), allocatable, target :: aux(:)
type(psb_c_vect_type), allocatable, target :: wwrk(:)
type(psb_c_vect_type), pointer :: ww, q, r, p, v,&
& s, z, f, rt, qt, uv
integer(psb_ipk_) :: itmax_, naux, mglob, it, itrace_,int_err(5),&
& n_row, n_col,istop_, itx, err_act
integer(psb_ipk_) :: np, me, ictxt
integer(psb_ipk_) :: debug_level, debug_unit
complex(psb_spk_) :: alpha, beta, rho, rho_old, sigma
real(psb_dpk_) :: derr
type(psb_itconv_type) :: stopdat
character(len=20) :: name
character(len=*), parameter :: methdname='CGS'
info = psb_success_
name = 'psb_ccgs'
call psb_erractionsave(err_act)
debug_unit = psb_get_debug_unit()
debug_level = psb_get_debug_level()
ictxt = desc_a%get_context()
Call psb_info(ictxt, me, np)
if (debug_level >= psb_debug_ext_)&
& write(debug_unit,*) me,' ',trim(name),': from psb_info',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_ = 2
Endif
call psb_chkvect(mglob,ione,x%get_nrows(),ione,ione,desc_a,info)
if (info == psb_success_) call psb_chkvect(mglob,ione,b%get_nrows(),ione,ione,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=11_psb_ipk_)
if (info == psb_success_) Call psb_geasb(wwrk,desc_a,info,mold=x%v)
if (info /= psb_success_) Then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
End If
q => wwrk(1)
qt => wwrk(2)
r => wwrk(3)
rt => wwrk(4)
p => wwrk(5)
v => wwrk(6)
uv => wwrk(7)
z => wwrk(8)
f => wwrk(9)
s => wwrk(10)
ww => wwrk(11)
If (Present(itmax)) Then
itmax_ = itmax
Else
itmax_ = 1000
Endif
If (Present(itrace)) Then
itrace_ = itrace
Else
itrace_ = 0
End If
itx = 0
call psb_init_conv(methdname,istop_,itrace_,itmax_,a,b,eps,desc_a,stopdat,info)
if (info /= psb_success_) Then
call psb_errpush(psb_err_from_subroutine_non_,name)
goto 9999
End If
restart: Do
! =
! = r0 = b-ax0
! =
if (itx >= itmax_) exit restart
it = 0
call psb_geaxpby(cone,b,czero,r,desc_a,info)
if (info == psb_success_) call psb_spmm(-cone,a,x,cone,r,desc_a,info,work=aux)
if (info == psb_success_) call psb_geaxpby(cone,r,czero,rt,desc_a,info)
if (info /= psb_success_) then
info=psb_err_from_subroutine_non_
call psb_errpush(info,name)
goto 9999
end if
! Perhaps we already satisfy the convergence criterion...
if (psb_check_conv(methdname,itx,x,r,desc_a,stopdat,info)) exit restart
if (info /= psb_success_) Then
call psb_errpush(psb_err_from_subroutine_non_,name)
goto 9999
End If
rho = czero
iteration: do
it = it + 1
itx = itx + 1
if (debug_level >= psb_debug_ext_) &
& write(debug_unit,*) me,' ',trim(name),'iteration: ',itx
rho_old = rho
rho = psb_gedot(rt,r,desc_a,info)
if (rho == czero) then
if (debug_level >= psb_debug_ext_) &
& write(debug_unit,*) me,' ',trim(name),&
& ' iteration breakdown r',rho
exit iteration
endif
if (it == 1) then
call psb_geaxpby(cone,r,czero,uv,desc_a,info)
if (info == psb_success_) call psb_geaxpby(cone,r,czero,p,desc_a,info)
else
beta = (rho/rho_old)
call psb_geaxpby(cone,r,czero,uv,desc_a,info)
if (info == psb_success_) call psb_geaxpby(beta,q,cone,uv,desc_a,info)
if (info == psb_success_) call psb_geaxpby(cone,q,beta,p,desc_a,info)
if (info == psb_success_) call psb_geaxpby(cone,uv,beta,p,desc_a,info)
end if
if (info == psb_success_) call prec%apply(p,f,desc_a,info,work=aux)
if (info == psb_success_) call psb_spmm(cone,a,f,czero,v,desc_a,info,&
& work=aux)
if (info /= psb_success_) then
call psb_errpush(psb_err_from_subroutine_,name,a_err='First loop part ')
goto 9999
end if
sigma = psb_gedot(rt,v,desc_a,info)
if (sigma == czero) then
if (debug_level >= psb_debug_ext_) &
& write(debug_unit,*) me,' ',trim(name),&
& ' iteration breakdown s1', sigma
exit iteration
endif
alpha = rho/sigma
if (info == psb_success_) call psb_geaxpby(cone,uv,czero,q,desc_a,info)
if (info == psb_success_) call psb_geaxpby(-alpha,v,cone,q,desc_a,info)
if (info == psb_success_) call psb_geaxpby(cone,uv,czero,s,desc_a,info)
if (info == psb_success_) call psb_geaxpby(cone,q,cone,s,desc_a,info)
if (info == psb_success_) call prec%apply(s,z,desc_a,info,work=aux)
if (info == psb_success_) call psb_geaxpby(alpha,z,cone,x,desc_a,info)
if (info == psb_success_) call psb_spmm(cone,a,z,czero,qt,desc_a,info,&
& work=aux)
if (info == psb_success_) call psb_geaxpby(-alpha,qt,cone,r,desc_a,info)
if (info /= psb_success_) then
call psb_errpush(psb_err_from_subroutine_,name,a_err='X update ')
goto 9999
end if
if (psb_check_conv(methdname,itx,x,r,desc_a,stopdat,info)) exit restart
if (info /= psb_success_) Then
call psb_errpush(psb_err_from_subroutine_non_,name)
goto 9999
End If
end do iteration
end do restart
call psb_end_conv(methdname,itx,desc_a,stopdat,info,derr,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 continue
call psb_erractionrestore(err_act)
if (err_act == psb_act_abort_) then
call psb_error()
return
end if
return
End Subroutine psb_ccgs_vect