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amg4psblas/examples/fileread/mld_sexample_ml.f90

378 lines
12 KiB
Fortran

!!$
!!$
!!$ MLD2P4 version 2.0
!!$ MultiLevel Domain Decomposition Parallel Preconditioners Package
!!$ based on PSBLAS (Parallel Sparse BLAS version 3.0)
!!$
!!$ (C) Copyright 2008,2009,2010,2012,2013
!!$
!!$ Salvatore Filippone University of Rome Tor Vergata
!!$ Alfredo Buttari CNRS-IRIT, Toulouse
!!$ Pasqua D'Ambra ICAR-CNR, Naples
!!$ Daniela di Serafino Second University of Naples
!!$
!!$ 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 MLD2P4 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 MLD2P4 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: mld_sexample_ml.f90
!
! This sample program solves a linear system by using BiCGStab coupled with
! one of the following multi-level preconditioner, as explained in Section 6.1
! of the MLD2P4 User's and Reference Guide:
! - choice = 1, default multi-level Schwarz preconditioner (Sec. 6.1, Fig. 2)
! - choice = 2, hybrid three-level Schwarz preconditioner (Sec. 6.1, Fig. 3)
! - choice = 3, additive three-level Schwarz preconditioner (Sec. 6.1, Fig. 4)
!
! The matrix and the rhs are read from files (if an rhs is not available, the
! unit rhs is set).
!
program mld_sexample_ml
use psb_base_mod
use mld_prec_mod
use psb_krylov_mod
use psb_util_mod
use data_input
implicit none
! input file parameters
character(len=40) :: mtrx_file, rhs_file
character(len=2) :: filefmt
! sparse matrices
type(psb_sspmat_type) :: A, aux_A
! descriptor of sparse matrices
type(psb_desc_type):: desc_A
! preconditioner
type(mld_sprec_type) :: P
! right-hand side, solution and residual vectors
real(psb_spk_), allocatable , save :: b(:), x(:), r(:), &
& x_glob(:), r_glob(:)
real(psb_spk_), allocatable, target :: aux_b(:,:)
real(psb_spk_), pointer :: b_glob(:)
! solver and preconditioner parameters
real(psb_spk_) :: tol, err
integer :: itmax, iter, istop
integer :: nlev
! parallel environment parameters
integer :: ictxt, iam, np
! other variables
integer :: choice
integer :: i,info,j,m_problem
integer(psb_long_int_k_) :: amatsize, precsize, descsize
integer :: ierr, ircode
real(psb_dpk_) :: t1, t2, tprec
real(psb_spk_) :: resmx, resmxp
character(len=20) :: name
integer, parameter :: iunit=12
! initialize the parallel environment
call psb_init(ictxt)
call psb_info(ictxt,iam,np)
if (iam < 0) then
! This should not happen, but just in case
call psb_exit(ictxt)
stop
endif
name='mld_sexample_ml'
if(psb_get_errstatus() /= 0) goto 9999
info=psb_success_
call psb_set_errverbosity(2)
!
! Hello world
!
if (iam == psb_root_) then
write(*,*) 'Welcome to MLD2P4 version: ',mld_version_string_
write(*,*) 'This is the ',trim(name),' sample program'
end if
! get parameters
call get_parms(ictxt,mtrx_file,rhs_file,filefmt,choice,itmax,tol)
call psb_barrier(ictxt)
t1 = psb_wtime()
! read and assemble the matrix A and the right-hand side b
! using PSBLAS routines for sparse matrix / vector management
if (iam == psb_root_) then
select case(psb_toupper(filefmt))
case('MM')
! For Matrix Market we have an input file for the matrix
! and an (optional) second file for the RHS.
call mm_mat_read(aux_a,info,iunit=iunit,filename=mtrx_file)
if (info == psb_success_) then
if (rhs_file /= 'NONE') then
call mm_vet_read(aux_b,info,iunit=iunit,filename=rhs_file)
end if
end if
case ('HB')
! For Harwell-Boeing we have a single file which may or may not
! contain an RHS.
call hb_read(aux_a,info,iunit=iunit,b=aux_b,filename=mtrx_file)
case default
info = -1
write(0,*) 'Wrong choice for fileformat ', filefmt
end select
if (info /= psb_success_) then
write(0,*) 'Error while reading input matrix '
call psb_abort(ictxt)
end if
m_problem = aux_a%get_nrows()
call psb_bcast(ictxt,m_problem)
! At this point aux_b may still be unallocated
if (psb_size(aux_b,1) == m_problem) then
! if any rhs were present, broadcast the first one
write(0,'("Ok, got an rhs ")')
b_glob =>aux_b(:,1)
else
write(*,'("Generating an rhs...")')
write(*,'(" ")')
call psb_realloc(m_problem,1,aux_b,ircode)
if (ircode /= 0) then
call psb_errpush(psb_err_alloc_dealloc_,name)
goto 9999
endif
b_glob => aux_b(:,1)
do i=1, m_problem
b_glob(i) = 1.d0
enddo
endif
call psb_bcast(ictxt,b_glob(1:m_problem))
else
call psb_bcast(ictxt,m_problem)
call psb_realloc(m_problem,1,aux_b,ircode)
if (ircode /= 0) then
call psb_errpush(psb_err_alloc_dealloc_,name)
goto 9999
endif
b_glob =>aux_b(:,1)
call psb_bcast(ictxt,b_glob(1:m_problem))
end if
call psb_barrier(ictxt)
if (iam == psb_root_) write(*,'("Partition type: block")')
call psb_matdist(aux_A, A, ictxt, &
& desc_A,b_glob,b,info, parts=part_block)
t2 = psb_wtime() - t1
call psb_amx(ictxt, t2)
if (iam == psb_root_) then
write(*,'(" ")')
write(*,'("Time to read and partition matrix : ",es12.5)')t2
write(*,'(" ")')
end if
select case(choice)
case(1)
! initialize the default multi-level preconditioner, i.e. hybrid
! Schwarz, using RAS (with overlap 1 and ILU(0) on the blocks)
! as post-smoother and 4 block-Jacobi sweeps (with UMFPACK LU
! on the blocks) as distributed coarse-level solver
call mld_precinit(P,'ML',info)
case(2)
! set a three-level hybrid Schwarz preconditioner, which uses
! block Jacobi (with ILU(0) on the blocks) as post-smoother,
! a coarsest matrix replicated on the processors, and the
! LU factorization from UMFPACK as coarse-level solver
call mld_precinit(P,'ML',info,nlev=3)
call mld_precset(P,mld_smoother_type_,'BJAC',info)
call mld_precset(P,mld_coarse_mat_,'REPL',info)
call mld_precset(P,mld_coarse_solve_,'UMF',info)
case(3)
! set a three-level additive Schwarz preconditioner, which uses
! RAS (with overlap 1 and ILU(0) on the blocks) as pre- and
! post-smoother, and 5 block-Jacobi sweeps (with UMFPACK LU
! on the blocks) as distributed coarsest-level solver
call mld_precinit(P,'ML',info,nlev=3)
call mld_precset(P,mld_ml_type_,'ADD',info)
call mld_precset(P,mld_smoother_pos_,'TWOSIDE',info)
call mld_precset(P,mld_coarse_sweeps_,5,info)
end select
! build the preconditioner
call psb_barrier(ictxt)
t1 = psb_wtime()
call mld_precbld(A,desc_A,P,info)
tprec = psb_wtime()-t1
call psb_amx(ictxt, tprec)
if (info /= psb_success_) then
call psb_errpush(psb_err_from_subroutine_,name,a_err='psb_precbld')
goto 9999
end if
! set the initial guess
call psb_geall(x,desc_A,info)
x(:) =0.0
call psb_geasb(x,desc_A,info)
! solve Ax=b with preconditioned BiCGSTAB
call psb_barrier(ictxt)
t1 = psb_wtime()
call psb_krylov('BICGSTAB',A,P,b,x,tol,desc_A,info,itmax,iter,err,itrace=1,istop=2)
t2 = psb_wtime() - t1
call psb_amx(ictxt,t2)
call psb_geall(r,desc_A,info)
r(:) =0.0
call psb_geasb(r,desc_A,info)
call psb_geaxpby(sone,b,szero,r,desc_A,info)
call psb_spmm(-sone,A,x,sone,r,desc_A,info)
call psb_genrm2s(resmx,r,desc_A,info)
call psb_geamaxs(resmxp,r,desc_A,info)
amatsize = a%sizeof()
descsize = desc_a%sizeof()
precsize = p%sizeof()
call psb_sum(ictxt,amatsize)
call psb_sum(ictxt,descsize)
call psb_sum(ictxt,precsize)
call mld_precdescr(P,info)
if (iam == psb_root_) then
write(*,'(" ")')
write(*,'("Matrix: ",A)')mtrx_file
write(*,'("Computed solution on ",i8," processors")')np
write(*,'("Iterations to convergence : ",i6)')iter
write(*,'("Error estimate on exit : ",es12.5)')err
write(*,'("Time to build prec. : ",es12.5)')tprec
write(*,'("Time to solve system : ",es12.5)')t2
write(*,'("Time per iteration : ",es12.5)')t2/(iter)
write(*,'("Total time : ",es12.5)')t2+tprec
write(*,'("Residual 2-norm : ",es12.5)')resmx
write(*,'("Residual inf-norm : ",es12.5)')resmxp
write(*,'("Total memory occupation for A : ",i12)')amatsize
write(*,'("Total memory occupation for DESC_A : ",i12)')descsize
write(*,'("Total memory occupation for PREC : ",i12)')precsize
end if
call psb_gather(x_glob,x_col,desc_a,info,root=psb_root_)
if (info == psb_success_) &
& call psb_gather(r_glob,r_col,desc_a,info,root=psb_root_)
if (info /= psb_success_) goto 9999
if (iam == psb_root_) then
write(0,'(" ")')
write(0,'("Saving x on file")')
write(20,*) 'matrix: ',mtrx_file
write(20,*) 'computed solution on ',np,' processors.'
write(20,*) 'iterations to convergence: ',iter
write(20,*) 'error estimate (infinity norm) on exit:', &
& ' ||r||/(||a||||x||+||b||) = ',err
write(20,*) 'max residual = ',resmx, resmxp
write(20,'(a8,4(2x,a20))') 'I','X(I)','R(I)','B(I)'
do i=1,m_problem
write(20,998) i,x_glob(i),r_glob(i),b_glob(i)
enddo
end if
998 format(i8,4(2x,g20.14))
993 format(i6,4(1x,e12.6))
! deallocate the data structures
call psb_gefree(b, desc_A,info)
call psb_gefree(x, desc_A,info)
call psb_spfree(A, desc_A,info)
call mld_precfree(P,info)
call psb_cdfree(desc_A,info)
9999 continue
if(info /= psb_success_) then
call psb_error(ictxt)
end if
call psb_exit(ictxt)
stop
contains
!
! get parameters from standard input
!
subroutine get_parms(ictxt,mtrx,rhs,filefmt,choice,itmax,tol)
use psb_base_mod
implicit none
integer :: ictxt, choice, itmax
real(psb_spk_) :: tol
character(len=*) :: mtrx, rhs,filefmt
integer :: iam, np
call psb_info(ictxt,iam,np)
if (iam == psb_root_) then
! read input parameters
call read_data(mtrx,5)
call read_data(rhs,5)
call read_data(filefmt,5)
call read_data(choice,5)
call read_data(itmax,5)
call read_data(tol,5)
end if
call psb_bcast(ictxt,mtrx)
call psb_bcast(ictxt,rhs)
call psb_bcast(ictxt,filefmt)
call psb_bcast(ictxt,choice)
call psb_bcast(ictxt,itmax)
call psb_bcast(ictxt,tol)
end subroutine get_parms
end program mld_sexample_ml