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psblas3/krylov/psb_dkrylov.f90

216 lines
9.4 KiB
Fortran

!!$
!!$ Parallel Sparse BLAS version 3.4
!!$ (C) Copyright 2006, 2010, 2015
!!$ 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
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!!$ 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_krylov_mod.f90
! Interfaces for Krylov subspace iterative methods.
!
!
! Subroutine: psb_dkrylov
!
! Front-end for the Krylov subspace iterations, realversion
!
! Arguments:
!
! methd - character The specific method; can take the values:
! CG
! CGS
! BICG
! BICGSTAB
! BICGSTABL
! RGMRES
!
! a - type(psb_dspmat_type) Input: sparse matrix containing A.
! prec - class(psb_dprec_type) Input: preconditioner
! b - real,dimension(:) Input: vector containing the
! right hand side B
! x - real,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.
! err - real (optional) Output: error estimate on exit
! itrace - integer(optional) Input: print an informational message
! with the error estimate every itrace
! iterations
! irst - integer(optional) Input: restart parameter for RGMRES and
! BICGSTAB(L) methods
! istop - integer(optional) Input: stopping criterion, or how
! to estimate the error.
! 1: err = |r|/(|a||x|+|b|)
! 2: err = |r|/|b|
! where r is the (preconditioned, recursive
! estimate of) residual
!
Subroutine psb_dkrylov_vect(method,a,prec,b,x,eps,desc_a,info,&
& itmax,iter,err,itrace,irst,istop,cond)
use psb_base_mod
use psb_prec_mod,only : psb_dprec_type
use psb_krylov_mod, psb_protect_name => psb_dkrylov_vect
character(len=*) :: method
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, irst,istop
integer(psb_ipk_), Optional, Intent(out) :: iter
Real(psb_dpk_), Optional, Intent(out) :: err,cond
abstract interface
subroutine psb_dkryl_vect(a,prec,b,x,eps,&
& desc_a,info,itmax,iter,err,itrace,istop)
import :: psb_ipk_, psb_dpk_, psb_desc_type, &
& psb_dspmat_type, psb_dprec_type, psb_d_vect_type
type(psb_dspmat_type), intent(in) :: a
type(psb_desc_type), intent(in) :: desc_a
type(psb_d_vect_type), Intent(inout) :: b
type(psb_d_vect_type), Intent(inout) :: x
real(psb_dpk_), intent(in) :: eps
class(psb_dprec_type), intent(inout) :: prec
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
end subroutine psb_dkryl_vect
Subroutine psb_dkryl_rest_vect(a,prec,b,x,eps,desc_a,info,&
&itmax,iter,err, itrace,irst,istop)
import :: psb_ipk_, psb_dpk_, psb_desc_type, &
& psb_dspmat_type, psb_dprec_type, psb_d_vect_type
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, irst,istop
integer(psb_ipk_), Optional, Intent(out) :: iter
Real(psb_dpk_), Optional, Intent(out) :: err
end subroutine psb_dkryl_rest_vect
Subroutine psb_dkryl_cond_vect(a,prec,b,x,eps,desc_a,info,&
&itmax,iter,err, itrace,istop,cond)
import :: psb_ipk_, psb_dpk_, psb_desc_type, &
& psb_dspmat_type, psb_dprec_type, psb_d_vect_type
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
end subroutine psb_dkryl_cond_vect
end interface
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
integer(psb_ipk_) :: ictxt,me,np,err_act
character(len=20) :: name
info = psb_success_
name = 'psb_krylov'
call psb_erractionsave(err_act)
ictxt=desc_a%get_context()
call psb_info(ictxt, me, np)
! Default return for COND
if (present(cond)) cond = dzero
select case(psb_toupper(method))
case('CG')
call psb_dcg_vect(a,prec,b,x,eps,desc_a,info,&
&itmax,iter,err,itrace,istop,cond)
case('FCG')
call psb_dfcg_vect(a,prec,b,x,eps,desc_a,info,&
&itmax,iter,err,itrace,istop,cond)
case('GCR')
call psb_dgcr_vect(a,prec,b,x,eps,desc_a,info,&
&itmax,iter,err,itrace,istop)
case('CGS')
call psb_dcgs_vect(a,prec,b,x,eps,desc_a,info,&
&itmax,iter,err,itrace,istop)
case('BICG')
call psb_dbicg_vect(a,prec,b,x,eps,desc_a,info,&
&itmax,iter,err,itrace,istop)
case('BICGSTAB')
call psb_dcgstab_vect(a,prec,b,x,eps,desc_a,info,&
&itmax,iter,err,itrace,istop)
case('RGMRES')
call psb_drgmres_vect(a,prec,b,x,eps,desc_a,info,&
&itmax,iter,err,itrace,irst,istop)
case('BICGSTABL')
call psb_dcgstabl_vect(a,prec,b,x,eps,desc_a,info,&
&itmax,iter,err,itrace,irst,istop)
case default
if (me == 0) write(psb_err_unit,*) trim(name),&
& ': Warning: Unknown method ',method,&
& ', defaulting to BiCGSTAB'
call psb_dcgstab_vect(a,prec,b,x,eps,desc_a,info,&
&itmax,iter,err,itrace,istop)
end select
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(ictxt,err_act)
return
end subroutine psb_dkrylov_vect